FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation vulnerability. The TLS hostname matcher (tls_match_hostname() in libfreerdp/crypto/tls.c) treats a wildcard pattern such as *.example.com as matching any hostname ending in .example.com, so it incorrectly accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's X509_check_host() rejects). This weakens TLS server authentication under wildcard-certificate conditions.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-106202 advisory.

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation     vulnerability. The TLS hostname matcher (tls_match_hostname() in libfreerdp/crypto/tls.c) treats a     wildcard pattern such as *.example.com as matching any hostname ending in .example.com, so it incorrectly     accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's     X509_check_host() rejects). This weakens TLS server authentication under wildcard-certificate conditions.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-2111 advisory.

    FreeRDP before 3.28.0 treats lines beginning with forward slash in RDP files as raw command-line options,     exposing the entire CLI parser surface to untrusted files. Attackers can craft malicious RDP files with     /rdp2tcp, /cert:ignore, or /drive options to execute arbitrary commands, bypass certificate validation, or     expose local filesystems without user interaction. (CVE-2026-64624)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains multiple TLS certificate identity validation     weaknesses in tls_verify_certificate(), tls_match_hostname(), and x509_utils_get_dns_names(). Because     FreeRDP performs custom Common Name and DNS SAN string matching instead of using OpenSSL's length-aware     identity validation APIs, it (1) truncates DNS SAN values at embedded NUL bytes (accepting e.g.
    'victim.example\0.attacker.example' as 'victim.example'), (2) accepts a matching Common Name even when     non-matching DNS SAN entries are present, and (3) accepts IP-literal targets via DNS/CN matching without     comparing iPAddress SANs. Under a trusted or misissued certificate chain, an attacker positioned to     present such a certificate can bypass server identity verification, weakening TLS server authentication.
    (CVE-2026-66402)

    FreeRDP before 3.29.0 contains a null pointer dereference vulnerability in smartcard cache request     decoders that accept NULL NDR pointers for LookupName in SCARD_IOCTL_READCACHEA and     SCARD_IOCTL_WRITECACHEA operations. When smartcard emulation is enabled, attackers can send crafted     smartcard cache requests with NULL lookup-name pointers to trigger strlen() on a null pointer, causing     client process termination. (CVE-2026-67288)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the     server-controlled RDP redirection TargetNetAddress field. This value is copied into the client's     ServerHostname and, when the client connects through an HTTP proxy, is written directly into the proxy     CONNECT request line and Host header by http_proxy_connect() without filtering. A malicious or compromised     RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary     headers/requests into the HTTP proxy CONNECT request. (CVE-2026-67289)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a heap out-of-bounds read in     update_process_glyph_fragments()/glyph_cache_fragment_put() in libfreerdp/cache/glyph.c. When handling a     GLYPH_FRAGMENT_ADD update, the code reads a one-byte server-controlled declared fragment size but does not     verify it fits within the remaining received buffer before allocating and copying that many bytes. A     malicious RDP server can send a short fragment with an oversized declared size, causing the client to read     beyond the allocated buffer, resulting in an out-of-bounds read and client crash. (CVE-2026-67291)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation     vulnerability. The TLS hostname matcher (tls_match_hostname() in libfreerdp/crypto/tls.c) treats a     wildcard pattern such as *.example.com as matching any hostname ending in .example.com, so it incorrectly     accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's     X509_check_host() rejects). This weakens TLS server authentication under wildcard-certificate conditions.
    (CVE-2026-67293)

    FreeRDP before 3.29.0 improperly validates the Extended Key Usage (EKU) purpose of the peer certificate     during client-side server TLS authentication. In x509_utils_verify(), when server-purpose     (X509_PURPOSE_SSL_SERVER) verification fails, the code falls back to client-purpose and any-purpose     verification, so a trusted, hostname-matching certificate valid only for clientAuth can be accepted as the     RDP server certificate. In environments relying on EKU separation between client and server certificates,     this allows a clientAuth-only certificate issued by a trusted CA to bypass server certificate purpose     validation. (CVE-2026-67294)

    FreeRDP before 3.29.0 fails to properly validate server-supplied RDPDR paths in drive redirection,     allowing attackers to access prefix-sibling paths outside the configured shared root. A malicious RDP     server can read, write, delete, and enumerate files in sibling directories by sending non-rooted paths     that bypass the shared-root boundary check. (CVE-2026-67295)

    FreeRDP before 3.29.0 fails to enforce the RESPONSE_SIZE_LIMIT when processing Transfer-Encoding: chunked     HTTP responses in http_response_recv_body(). Attackers controlling a malicious RD Gateway endpoint can     send oversized chunked response bodies to exhaust client memory resources without triggering the     configured size limit. (CVE-2026-67297)

    FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler     (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header,     the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first     verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned     integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check     (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-     of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash     the server. Fixed in FreeRDP 3.29.0. (CVE-2026-67298)

    FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message proxy for     WINDOW_ICON_ORDER when AsyncUpdate is enabled (e.g. xfreerdp /async-update). In     update_message_WindowIcon() a shallow CopyMemory() overwrites a freshly allocated lParam->iconInfo with     the parser-owned windowIcon->iconInfo pointer. After the parser callback returns,     update_recv_window_info_order() frees window_icon.iconInfo, but the queued async message still retains and     later dispatches that stale pointer. A malicious or compromised RDP server sending a crafted RAIL Window     Alternate Secondary Order with WINDOW_ORDER_ICON can trigger use-after-free, leading to memory corruption     and client crash. (CVE-2026-67299)

    FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message     proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a     malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies     structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects,     icon buffers). The parser frees those nested buffers after the callback returns, so the queued async     message later dispatches stale pointers, potentially causing memory corruption or a client crash.
    (CVE-2026-67300)

    FreeRDP before 3.29.0 contains out-of-bounds read vulnerabilities in the async update message proxy for     the PolygonSC and PolygonCB primary drawing orders. When AsyncUpdate is enabled (e.g., xfreerdp /async-     update), update_message_PolygonSC() and update_message_PolygonCB() allocate a fresh points array but copy     point data from the address of the order structure instead of from polygonSC->points / polygonCB->points,     resulting in a client-side out-of-bounds read. A malicious or compromised RDP server sending crafted     PolygonSC/PolygonCB update orders can trigger memory disclosure or a client crash. (CVE-2026-67301)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a divide-by-zero vulnerability in the rdpecam     camera redirection client. ecam_dev_process_start_streams_request() parses a server-controlled     CAM_MEDIA_TYPE_DESCRIPTION from a StartStreamsRequest PDU but validates only Format and Flags, not     FrameRateDenominator. When a malicious or compromised RDP server sends a StartStreamsRequest with     FrameRateDenominator set to zero, ecam_encoder_context_init() (channels/rdpecam/client/encoding.c)     computes FrameRateNumerator / FrameRateDenominator, causing an integer division by zero (SIGFPE) and     termination of the FreeRDP client process. Camera redirection must be enabled on the client for the     channel to be reachable. Fixed in FreeRDP 3.29.0. (CVE-2026-67302)

    FreeRDP before 3.29.0 contains a reachable assertion (WINPR_ASSERT(OutputBufferLength == BytesReturned))     in serial_process_irp_device_control() in channels/serial/client/serial_main.c. When serial device     redirection is enabled and a server-controlled IRP_MJ_DEVICE_CONTROL request specifies an unsupported     IOCTL with a non-zero OutputBufferLength, CommDeviceIoControl() can fail with BytesReturned = 0, causing     the mismatch to trigger the assertion and abort the client process (denial of service). (CVE-2026-67303)

    FreeRDP before 3.29.0 contains a null pointer dereference vulnerability in smartcard device control     request cleanup when reader-state decoding fails. Attackers can send malformed smartcard IRP requests with     non-zero cReaders and truncated reader-state data to crash the process via null pointer access in     free_reader_states functions. (CVE-2026-67304)

    FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE     bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only in     libfreerdp/codec/planar.c. Only the 1-byte control byte is bounds-checked; the subsequent 0-15 attacker-     declared raw bytes are read without validating that the source buffer contains them. A malicious or     compromised RDP server can send a truncated planar-encoded bitmap or surface update (reachable via both     the Bitmap Update PDU and RDPGFX Surface Command paths) that causes the client to read past the end of the     source buffer. The issue is fixed in FreeRDP 3.29.0. (CVE-2026-67306)

    FreeRDP before 3.29.0 contains integer overflow vulnerabilities in the audio input redirection channel     (audin) across ALSA, sndio, WinMM, and OpenSL ES backends that fail to validate the FramesPerPacket     parameter from RDP servers. Attackers can supply a malicious FramesPerPacket value causing allocation size     wraparound, resulting in heap-based buffer overflow on ALSA or denial of service on all platforms.
    (CVE-2026-68580)

    FreeRDP before 3.30.0 contains an out-of-bounds vulnerability in kerberos_DecryptMessage()     (winpr/libwinpr/sspi/Kerberos/kerberos.c). The 16-bit EC (extra count) field of a peer-supplied GSS Wrap     token (RFC 4121) is used directly in pointer arithmetic to locate the encrypted regions without being     bounds-checked, while only RRC and the total buffer length are validated. A malicious peer (server or     client) can supply a large EC value (up to 0xFFFF) during CredSSP/NLA authentication, moving the decrypt     operation's base pointers past the end of the ~60-byte token buffer. Because the AES-CTS-HMAC enctypes     decrypt in place before the HMAC integrity check, this results in an out-of-bounds read and in-place out-     of-bounds write, potentially leading to information disclosure, memory corruption, or denial of service.
    (CVE-2026-72745)

    FreeRDP before 3.30.0 contains a server-side authentication bypass in the RDSTLS handshake. When a server     is configured with RdstlsSecurity = TRUE, the handshake dispatches inbound PDUs based solely on the     attacker-supplied wire pduType without verifying that the received PDU is the one required at the current     step. Because the rdpRdstls object is calloc-zeroed, its resultCode defaults to 0 (RDSTLS_RESULT_SUCCESS).
    An unauthenticated remote client can send a Capabilities PDU instead of the required Authentication     Request PDU; rdstls_process_capabilities() returns success without ever setting resultCode, so the server     responds with an AUTHRSP carrying resultCode SUCCESS and treats the session as authenticated without     evaluating any password, redirection GUID, or auto-reconnect cookie. This affects the released FreeRDP 3.x     series (e.g., 3.27.1) and master HEAD; at the time of the advisory no patched version was available.
    (CVE-2026-72746)

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP server-side     RDSTLS in libfreerdp/core/rdstls.c accepts an attacker-supplied RDSTLS_TYPE_CAPABILITIES PDU while     rdstls_server_authenticate is waiting for RDSTLS_TYPE_AUTHREQ, leaving resultCode at RDSTLS_RESULT_SUCCESS     and allowing a remote unauthenticated client to bypass the RedirectionGuid, username, domain, or password     checks. This issue is fixed in version 3.30.0. (CVE-2026-73241)

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP's     winpr/libwinpr/sspi/Kerberos/kerberos.c kerberos_DecryptMessage function fails to bound the peer-     controlled GSS Wrap-token EC field before using it with RRC in IOV pointer offsets, allowing a malicious     RDP peer to trigger out-of-bounds reads and in-place writes during CredSSP/NLA Kerberos decryption. This     issue is fixed in version 3.30.0. (CVE-2026-73242)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of freerdp installed on the remote host is prior to 2.11.7-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3887 advisory.

    FreeRDP before 3.28.0 treats lines beginning with forward slash in RDP files as raw command-line options,     exposing the entire CLI parser surface to untrusted files. Attackers can craft malicious RDP files with     /rdp2tcp, /cert:ignore, or /drive options to execute arbitrary commands, bypass certificate validation, or     expose local filesystems without user interaction. (CVE-2026-64624)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains multiple TLS certificate identity validation     weaknesses in tls_verify_certificate(), tls_match_hostname(), and x509_utils_get_dns_names(). Because     FreeRDP performs custom Common Name and DNS SAN string matching instead of using OpenSSL's length-aware     identity validation APIs, it (1) truncates DNS SAN values at embedded NUL bytes (accepting e.g.
    'victim.example\0.attacker.example' as 'victim.example'), (2) accepts a matching Common Name even when     non-matching DNS SAN entries are present, and (3) accepts IP-literal targets via DNS/CN matching without     comparing iPAddress SANs. Under a trusted or misissued certificate chain, an attacker positioned to     present such a certificate can bypass server identity verification, weakening TLS server authentication.
    (CVE-2026-66402)

    FreeRDP before 3.29.0 contains a null pointer dereference vulnerability in smartcard cache request     decoders that accept NULL NDR pointers for LookupName in SCARD_IOCTL_READCACHEA and     SCARD_IOCTL_WRITECACHEA operations. When smartcard emulation is enabled, attackers can send crafted     smartcard cache requests with NULL lookup-name pointers to trigger strlen() on a null pointer, causing     client process termination. (CVE-2026-67288)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the     server-controlled RDP redirection TargetNetAddress field. This value is copied into the client's     ServerHostname and, when the client connects through an HTTP proxy, is written directly into the proxy     CONNECT request line and Host header by http_proxy_connect() without filtering. A malicious or compromised     RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary     headers/requests into the HTTP proxy CONNECT request. (CVE-2026-67289)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains a heap out-of-bounds read in     update_process_glyph_fragments()/glyph_cache_fragment_put() in libfreerdp/cache/glyph.c. When handling a     GLYPH_FRAGMENT_ADD update, the code reads a one-byte server-controlled declared fragment size but does not     verify it fits within the remaining received buffer before allocating and copying that many bytes. A     malicious RDP server can send a short fragment with an oversized declared size, causing the client to read     beyond the allocated buffer, resulting in an out-of-bounds read and client crash. (CVE-2026-67291)

    FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation     vulnerability. The TLS hostname matcher (tls_match_hostname() in libfreerdp/crypto/tls.c) treats a     wildcard pattern such as *.example.com as matching any hostname ending in .example.com, so it incorrectly     accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's     X509_check_host() rejects). This weakens TLS server authentication under wildcard-certificate conditions.
    (CVE-2026-67293)

    FreeRDP before 3.29.0 improperly validates the Extended Key Usage (EKU) purpose of the peer certificate     during client-side server TLS authentication. In x509_utils_verify(), when server-purpose     (X509_PURPOSE_SSL_SERVER) verification fails, the code falls back to client-purpose and any-purpose     verification, so a trusted, hostname-matching certificate valid only for clientAuth can be accepted as the     RDP server certificate. In environments relying on EKU separation between client and server certificates,     this allows a clientAuth-only certificate issued by a trusted CA to bypass server certificate purpose     validation. (CVE-2026-67294)

    FreeRDP before 3.29.0 fails to properly validate server-supplied RDPDR paths in drive redirection,     allowing attackers to access prefix-sibling paths outside the configured shared root. A malicious RDP     server can read, write, delete, and enumerate files in sibling directories by sending non-rooted paths     that bypass the shared-root boundary check. (CVE-2026-67295)

    FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler     (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header,     the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first     verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned     integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check     (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-     of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash     the server. Fixed in FreeRDP 3.29.0. (CVE-2026-67298)

    FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message proxy for     WINDOW_ICON_ORDER when AsyncUpdate is enabled (e.g. xfreerdp /async-update). In     update_message_WindowIcon() a shallow CopyMemory() overwrites a freshly allocated lParam->iconInfo with     the parser-owned windowIcon->iconInfo pointer. After the parser callback returns,     update_recv_window_info_order() frees window_icon.iconInfo, but the queued async message still retains and     later dispatches that stale pointer. A malicious or compromised RDP server sending a crafted RAIL Window     Alternate Secondary Order with WINDOW_ORDER_ICON can trigger use-after-free, leading to memory corruption     and client crash. (CVE-2026-67299)

    FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message     proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a     malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies     structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects,     icon buffers). The parser frees those nested buffers after the callback returns, so the queued async     message later dispatches stale pointers, potentially causing memory corruption or a client crash.
    (CVE-2026-67300)

    FreeRDP before 3.29.0 contains out-of-bounds read vulnerabilities in the async update message proxy for     the PolygonSC and PolygonCB primary drawing orders. When AsyncUpdate is enabled (e.g., xfreerdp /async-     update), update_message_PolygonSC() and update_message_PolygonCB() allocate a fresh points array but copy     point data from the address of the order structure instead of from polygonSC->points / polygonCB->points,     resulting in a client-side out-of-bounds read. A malicious or compromised RDP server sending crafted     PolygonSC/PolygonCB update orders can trigger memory disclosure or a client crash. (CVE-2026-67301)

    FreeRDP versions 3.28.0 and earlier contain an out-of-bounds read vulnerability in the RDP6 planar RLE     bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only in     libfreerdp/codec/planar.c. Only the 1-byte control byte is bounds-checked; the subsequent 0-15 attacker-     declared raw bytes are read without validating that the source buffer contains them. A malicious or     compromised RDP server can send a truncated planar-encoded bitmap or surface update (reachable via both     the Bitmap Update PDU and RDPGFX Surface Command paths) that causes the client to read past the end of the     source buffer. The issue is fixed in FreeRDP 3.29.0. (CVE-2026-67306)

    FreeRDP before 3.29.0 contains integer overflow vulnerabilities in the audio input redirection channel     (audin) across ALSA, sndio, WinMM, and OpenSL ES backends that fail to validate the FramesPerPacket     parameter from RDP servers. Attackers can supply a malicious FramesPerPacket value causing allocation size     wraparound, resulting in heap-based buffer overflow on ALSA or denial of service on all platforms.
    (CVE-2026-68580)

    FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.29.0,     planar_decompress_plane_rle and planar_decompress_plane_rle_only in libfreerdp/codec/planar.c verify that     a control byte exists but do not verify that the source buffer contains the zero to fifteen raw bytes     declared by that control byte. A malicious RDP server can send a truncated planar bitmap or surface update     whose final control byte claims additional raw bytes, causing the decoder to read beyond pSrcData while     processing a color plane. This can crash the client and may disclose adjacent memory. This issue is fixed     in version 3.29.0. (CVE-2026-69159)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation     vulnerability. The TLS hostname matcher (tls_match_hostname() in libfreerdp/crypto/tls.c) treats a     wildcard pattern such as *.example.com as matching any hostname ending in .example.com, so it incorrectly     accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's     X509_check_host() rejects). This weakens TLS server authentication under wildcard-certificate conditions.
    (CVE-2026-67293)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
342881	Unity Linux 20.1050e / 20.1060e / 20.1070e Security Update: freerdp (UTSA-2026-106202)	Nessus	Unity Linux Local Security Checks	Local	critical
342051	Amazon Linux 2023 : freerdp, freerdp-devel, freerdp-libs (ALAS2023-2026-2111)	Nessus	Amazon Linux Local Security Checks	Local	critical
341869	Amazon Linux 2 : freerdp (ALAS-2026-3887)	Nessus	Amazon Linux Local Security Checks	Local	critical
331619	Linux Distros Unpatched Vulnerability : CVE-2026-67293	Nessus	Misc.	Local	critical

Detections

Analytics

CVE-2026-67293

critical

Tenable Plugins

critical

critical

critical

critical