A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).

The remote MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1872:12 advisory.

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)
      * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)

Tenable has extracted the preceding description block directly from the MiracleLinux 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 remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:68612 advisory.

    The libsoup packages provide an HTTP client and server library for GNOME.

    Security Fix(es):

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)

    * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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.

The remote Oracle Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-68235 advisory.

    - Fix CVE-2026-85197: http2 crash after connection destroyed
    - Fix CVE-2026-15711: Reject oversized WebSocket control frames
    - Fix CVE-2026-15709: bound decompressed WebSocket message size
    - Add patches for CVE-2026-4271 and CVE-2026-5119
    - Add patch for CVE-2026-1761
    - Fix CVE-2026-0719
    - Fix CVE-2025-14523
    - Add patch for CVE-2025-12105

Tenable has extracted the preceding description block directly from the Oracle 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.

The remote Oracle Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-68234 advisory.

    - Fix CVE-2026-15711: Reject oversized WebSocket control frames

Tenable has extracted the preceding description block directly from the Oracle 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.

The remote AlmaLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2026:68234 advisory.

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)
      * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)

Tenable has extracted the preceding description block directly from the AlmaLinux 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 remote AlmaLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2026:68235 advisory.

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)
      * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)
      * libsoup: libsoup: Heap use-after-free in libsoup HTTP/2 client on_data_read() via GOAWAY during body     upload (CVE-2026-85197)

Tenable has extracted the preceding description block directly from the AlmaLinux 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 remote RockyLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:68234 advisory.

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)

    * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)

Tenable has extracted the preceding description block directly from the RockyLinux 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 remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:68234 advisory.

    The libsoup packages provide an HTTP client and server library for GNOME.

    Security Fix(es):

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)

    * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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.

The remote Redhat Enterprise Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:68235 advisory.

    Libsoup is an HTTP library implementation in C. It was originally part of a SOAP (Simple Object Access     Protocol) implementation called Soup, but the SOAP and non-SOAP parts have now been split into separate     packages.  libsoup uses the Glib main loop and is designed to work well with GTK applications. This     enables GNOME applications to access HTTP servers on the network in a completely asynchronous fashion,     very similar to the Gtk+ programming model (a synchronous operation mode is also supported for those who     want it), but the SOAP parts were removed long ago.

    Security Fix(es):

    * SoupWebsocketExtensionDeflate: libsoup: libsoup: WebSocket permessage-deflate Unbounded Decompression     Remote Denial of Service (CVE-2026-15709)

    * libsoup: SoupWebsocketConnection: libsoup: WebSocket remote denial of service via oversized control     frame protocol violation (CVE-2026-15711)

    * libsoup: libsoup: Heap use-after-free in libsoup HTTP/2 client on_data_read() via GOAWAY during body     upload (CVE-2026-85197)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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.

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-2159 advisory.

    A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The     extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary     limit on the output buffer size. While libsoup limits the incoming compressed frame size via     max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate     check for decompressed size (max_total_message_size) exists but executes only after inflation is complete,     and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can     exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded     memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).
    (CVE-2026-15709)

Tenable has extracted the preceding description block directly from the tested product 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 a vulnerability as referenced in the ALAS2023-2026-2160 advisory.

    A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The     extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary     limit on the output buffer size. While libsoup limits the incoming compressed frame size via     max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate     check for decompressed size (max_total_message_size) exists but executes only after inflation is complete,     and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can     exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded     memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).
    (CVE-2026-15709)

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

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

The remote Fedora 45 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-ce24b84bb1 advisory.

    Fixes lots of CVEs: see the fixes section for details

Tenable has extracted the preceding description block directly from the Fedora 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 remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-fce2f41203 advisory.

    Fixes lots of CVEs: see the fixes section for details

Tenable has extracted the preceding description block directly from the Fedora 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 remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-3f60ccf61f advisory.

    Fixes lots of CVEs: see the fixes section for details

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

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

According to the versions of the libsoup packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    A flaw was found in SoupServer. This HTTP request smuggling vulnerability occurs because SoupServer     improperly handles requests that combine Transfer-Encoding: chunked and Connection: keep-alive headers. A     remote, unauthenticated client can exploit this by sending specially crafted requests, causing SoupServer     to fail to close the connection as required by RFC 9112. This allows the attacker to smuggle additional     requests over the persistent connection, leading to unintended request processing and potential denial-of-     service (DoS) conditions.(CVE-2026-1760)

    A flaw was found in libsoup. A remote attacker could exploit an unsigned to signed conversion error in the     `soup_body_input_stream_read_chunked()` function by sending a malicious HTTP request. This vulnerability     occurs when libsoup operates behind a non-libsoup proxy server or as a proxy in front of a non-libsoup     backend server. Successful exploitation can allow an attacker to bypass security controls, poison web     caches, or gain unauthorized access.(CVE-2026-6324)

    A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The     extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary     limit on the output buffer size. While libsoup limits the incoming compressed frame size via     max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate     check for decompressed size (max_total_message_size) exists but executes only after inflation is complete,     and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can     exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded     memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service     (DoS).(CVE-2026-15709)

Tenable has extracted the preceding description block directly from the EulerOS libsoup 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.

  - A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The     extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary     limit on the output buffer size. While libsoup limits the incoming compressed frame size via     max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate     check for decompressed size (max_total_message_size) exists but executes only after inflation is complete,     and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can     exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded     memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).
    (CVE-2026-15709)

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

ID	Name	Product	Family	Type	Severity
347925	MiracleLinux 9 : libsoup-2.72.0-16.el9_8.3 (AXSA:2026-1872:12)	Nessus	Miracle Linux Local Security Checks	Local	high
346985	RHEL 9 : libsoup (RHSA-2026:68612)	Nessus	Red Hat Local Security Checks	Local	high
346909	Oracle Linux 10 : libsoup3 (ELSA-2026-68235)	Nessus	Oracle Linux Local Security Checks	Local	high
346890	Oracle Linux 9 : libsoup (ELSA-2026-68234)	Nessus	Oracle Linux Local Security Checks	Local	high
346871	AlmaLinux 9 : libsoup (ALSA-2026:68234)	Nessus	Alma Linux Local Security Checks	Local	high
346869	AlmaLinux 10 : libsoup3 (ALSA-2026:68235)	Nessus	Alma Linux Local Security Checks	Local	high
346833	RockyLinux 9 : libsoup (RLSA-2026:68234)	Nessus	Rocky Linux Local Security Checks	Local	high
346441	RHEL 9 : libsoup (RHSA-2026:68234)	Nessus	Red Hat Local Security Checks	Local	high
346431	RHEL 10 : libsoup3 (RHSA-2026:68235)	Nessus	Red Hat Local Security Checks	Local	high
345792	Amazon Linux 2023 : libsoup3, libsoup3-devel (ALAS2023-2026-2159)	Nessus	Amazon Linux Local Security Checks	Local	high
345765	Amazon Linux 2023 : libsoup, libsoup-devel (ALAS2023-2026-2160)	Nessus	Amazon Linux Local Security Checks	Local	high
344981	Fedora 45 : libsoup3 (2026-ce24b84bb1)	Nessus	Fedora Local Security Checks	Local	medium
344486	Fedora 43 : libsoup3 (2026-fce2f41203)	Nessus	Fedora Local Security Checks	Local	medium
343791	Fedora 44 : libsoup3 (2026-3f60ccf61f)	Nessus	Fedora Local Security Checks	Local	medium
343693	EulerOS 2.0 SP12 : libsoup (EulerOS-SA-2026-3353)	Nessus	Huawei Local Security Checks	Local	medium
343635	EulerOS 2.0 SP12 : libsoup (EulerOS-SA-2026-3278)	Nessus	Huawei Local Security Checks	Local	medium
326908	Linux Distros Unpatched Vulnerability : CVE-2026-15709	Nessus	Misc.	Local	high

Detections

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CVE-2026-15709

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Tenable Plugins

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