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TencentOS Server 3: freerdp (TSSA-2026:0266)
critical Nessus Plugin ID 310961
Synopsis
The remote TencentOS Server 3 host is missing one or more security updates.Description
The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0266 advisory.Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:
CVE-2026-22852:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client when processing Audio Input (AUDIN) format lists. audin_process_formats reuses callback->formats_count across multiple MSG_SNDIN_FORMATS PDUs and writes past the newly allocated formats array, causing memory corruption and a crash. This vulnerability is fixed in 3.20.1.
CVE-2026-22854:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a heap-buffer-overflow occurs in drive read when a server-controlled read length is used to read file data into an IRP output stream buffer without a hard upper bound, allowing an oversized read to overwrite heap memory. This vulnerability is fixed in 3.20.1.
CVE-2026-22856:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a race in the serial channel IRP thread tracking allows a heap useafterfree when one thread removes an entry from serial->IrpThreads while another reads it. This vulnerability is fixed in 3.20.1.
CVE-2026-23732:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, FastGlyph parsing trusts cbData/remaining length and never validates against the minimum size implied by cx/cy. A malicious server can trigger a clientside global buffer overflow, causing a crash (DoS). Version 3.21.0 contains a patch for the issue.
CVE-2026-23948:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, a NULL pointer dereference vulnerability in rdp_write_logon_info_v2() allows a malicious RDP server to crash FreeRDP proxy by sending a specially crafted LogonInfoV2 PDU with cbDomain=0 or cbUserName=0. This vulnerability is fixed in 3.22.0.
CVE-2026-24491:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, video_timer can send client notifications after the control channel is closed, dereferencing a freed callback and triggering a use after free. This vulnerability is fixed in 3.22.0.
CVE-2026-24675:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, urb_select_interface can free the device's MS config on error but later code still dereferences it, leading to a use after free in libusb_udev_select_interface. This vulnerability is fixed in 3.22.0.
CVE-2026-24676:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, AUDIN format renegotiation frees the active format list while the capture thread continues using audin->format, leading to a use after free in audio_format_compatible. This vulnerability is fixed in 3.22.0.
CVE-2026-24679:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, The URBDRC client uses server-supplied interface numbers as array indices without bounds checks, causing an out-of-bounds read in libusb_udev_select_interface. This vulnerability is fixed in 3.22.0.
CVE-2026-24681:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, aAsynchronous bulk transfer completions can use a freed channel callback after URBDRC channel close, leading to a use after free in urb_write_completion. This vulnerability is fixed in 3.22.0.
CVE-2026-24683:
FreeRDP is a free implementation of the Remote Desktop Protocol. ainput_send_input_event caches channel_callback in a local variable and later uses it without synchronization; a concurrent channel close can free or reinitialize the callback, leading to a use after free. Prior to 3.22.0, This vulnerability is fixed in 3.22.0.
CVE-2026-24684:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, the RDPSND async playback thread can process queued PDUs after the channel is closed and internal state is freed, leading to a use after free in rdpsnd_treat_wave. This vulnerability is fixed in 3.22.0.
CVE-2026-31806:
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function processes SURFACE_BITS_COMMAND messages sent by the RDP server. When the command is handled using NSCodec, the bmp.width and bmp.height values provided by the server are not properly validated against the actual desktop dimensions. A malicious RDP server can supply crafted bmp.width and bmp.height values that exceed the expected surface size. Because these values are used during bitmap decoding and memory operations without proper bounds checking, this can lead to a heap buffer overflow. Since the attacker can also control the associated pixel data transmitted by the server, the overflow may be exploitable to overwrite adjacent heap memory. This vulnerability is fixed in 3.24.0.
Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Update the affected packages.See Also
Plugin Details
Severity: Critical
ID: 310961
File Name: tencentos_TSSA_2026_0266.nasl
Version: 1.1
Type: Local
Family: Tencent Local Security Checks
Published: 4/29/2026
Updated: 4/29/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.7
CVSS v2
Risk Factor: Critical
Base Score: 10
Temporal Score: 7.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
CVSS Score Source: CVE-2026-31806
CVSS v3
Risk Factor: Critical
Base Score: 9.8
Temporal Score: 8.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C
CVSS v4
Risk Factor: Critical
Base Score: 9.3
Threat Score: 8.9
Threat Vector: CVSS:4.0/E:P
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Vulnerability Information
CPE: p-cpe:/a:tencent:tencentos_server:freerdp, cpe:/o:tencent:tencentos_server:3
Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list
Exploit Available: true
Exploit Ease: Exploits are available
Patch Publication Date: 4/7/2026
Vulnerability Publication Date: 1/14/2026
Reference Information
CVE: CVE-2026-22852, CVE-2026-22854, CVE-2026-22856, CVE-2026-23732, CVE-2026-23948, CVE-2026-24491, CVE-2026-24675, CVE-2026-24676, CVE-2026-24679, CVE-2026-24681, CVE-2026-24683, CVE-2026-24684, CVE-2026-31806
IAVA: 2026-A-0099-S, 2026-A-0286