A flaw was found in libsoup, a library for handling HTTP requests. This vulnerability, known as a Use-After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application attempting to access memory that has already been freed, potentially causing application instability or crashes, resulting in a Denial of Service (DoS).

The Rocky Linux 10.1 host has packages installed that are affected by multiple vulnerabilities as referenced in the CIQ crlsa-2026_15968 advisory.

    * libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server (CVE-2026-4271)

    * libsoup: libsoup: Information disclosure via cleartext transmission of cookies during HTTPS tunnel     establishment (CVE-2026-5119)

Tenable has extracted the preceding description block directly from the CIQ 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-f3ca65c0c9 advisory.

    Fix for several CVEs

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-c8cfd2f2f9 advisory.

    Patches for several CVEs

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 Oracle Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-19143 advisory.

    - 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 SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2314-1 advisory.

    This update for libsoup fixes the following issues

    - CVE-2026-1801: HTTP Request Smuggling in soup_filter_input_stream_read_line() (bsc#1257649).
    - CVE-2026-4271: use-after-free in the HTTP/2 server when user signal handlers disconnect connections     during callback       execution (bsc#1259767).

Tenable has extracted the preceding description block directly from the SUSE 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 openSUSE 16 host has packages installed that are affected by a vulnerability as referenced in the openSUSE- SU-2026:20845-1 advisory.

    This update for libsoup fixes the following issue

    - CVE-2026-4271: use-after-free in the HTTP/2 server when user signal handlers disconnect connections     during callback       execution (bsc#1259767).

Tenable has extracted the preceding description block directly from the SUSE 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 Redhat Enterprise Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:19143 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):

    * libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server (CVE-2026-4271)

    * libsoup: libsoup: Information disclosure via cleartext transmission of cookies during HTTPS tunnel     establishment (CVE-2026-5119)

    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-2026:17482 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):

    * libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server (CVE-2026-4271)

    * libsoup: libsoup: Information disclosure via cleartext transmission of cookies during HTTPS tunnel     establishment (CVE-2026-5119)

    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 RockyLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:15968 advisory.

    * libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server (CVE-2026-4271)

    * libsoup: libsoup: Information disclosure via cleartext transmission of cookies during HTTPS tunnel     establishment (CVE-2026-5119)

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 Oracle Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-15968 advisory.

    - 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 Redhat Enterprise Linux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:15968 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):

    * libsoup: libsoup: Denial of Service via Use-After-Free in HTTP/2 server (CVE-2026-4271)

    * libsoup: libsoup: Information disclosure via cleartext transmission of cookies during HTTPS tunnel     establishment (CVE-2026-5119)

    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 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, a library for handling HTTP requests. This vulnerability, known as a Use-     After-Free, occurs in the HTTP/2 server implementation. A remote attacker can exploit this by sending     specially crafted HTTP/2 requests that cause authentication failures. This can lead to the application     attempting to access memory that has already been freed, potentially causing application instability or     crashes, resulting in a Denial of Service (DoS). (CVE-2026-4271)

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

ID	Name	Product	Family	Type	Severity
356317	Rocky Linux 10.1 [CIQ] Security Update: libsoup3 / libsoup3-debuginfo / libsoup3-debugsource / etc Multiple Vulnerabilities (crlsa-2026_15968)	Nessus	Rocky Linux Local Security Checks	Local	high
341036	Fedora 43 : libsoup3 (2026-f3ca65c0c9)	Nessus	Fedora Local Security Checks	Local	high
335488	Fedora 44 : libsoup3 (2026-c8cfd2f2f9)	Nessus	Fedora Local Security Checks	Local	high
327497	Oracle Linux 10 : libsoup3 (ELSA-2026-19143)	Nessus	Oracle Linux Local Security Checks	Local	high
321043	SUSE SLED15 / SLES15 Security Update : libsoup (SUSE-SU-2026:2314-1)	Nessus	SuSE Local Security Checks	Local	medium
318188	openSUSE 16 Security Update : libsoup (openSUSE-SU-2026:20845-1)	Nessus	SuSE Local Security Checks	Local	high
315509	RHEL 10 : libsoup3 (RHSA-2026:19143)	Nessus	Red Hat Local Security Checks	Local	high
314643	RHEL 10 : libsoup3 (RHSA-2026:17482)	Nessus	Red Hat Local Security Checks	Local	high
314423	RockyLinux 10 : libsoup3 (RLSA-2026:15968)	Nessus	Rocky Linux Local Security Checks	Local	high
314281	Oracle Linux 10 : libsoup3 (ELSA-2026-15968)	Nessus	Oracle Linux Local Security Checks	Local	high
314244	RHEL 10 : libsoup3 (RHSA-2026:15968)	Nessus	Red Hat Local Security Checks	Local	high
302759	Linux Distros Unpatched Vulnerability : CVE-2026-4271	Nessus	Misc.	Local	high

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CVE-2026-4271

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