Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity resolution handling.

According to the versions of the libxml2 packages installed, the EulerOS Virtualization installation on the remote host is affected by the following vulnerabilities :

    Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a     remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity     resolution handling.(CVE-2026-6653)

    libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in
    --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper     bounds checking.By supplying an overly long input line, an attacker can overflow internal buffers     (command, arg, and argv) during input parsing. This results in memory corruption within the stack     frame.Successful exploitation may cause a crash or potentially allow arbitrary code execution in the     context of the xmlcatalog process.This issue has been fixed in the commit c2e233fc.NOTE:The maintainers of     this project did not agree that this issue is a vulnerability and considered it a bug.(CVE-2026-11979)

Tenable has extracted the preceding description block directly from the EulerOS Virtualization libxml2 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 libxml2 packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

    Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a     remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity     resolution handling.(CVE-2026-6653)

    libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in
    --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper     bounds checking.
    By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv)     during input parsing. This results in memory corruption within the stack frame.
    Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of     the xmlcatalog process.

    This issue has been fixed in the commit c2e233fc.

    NOTE:
    The maintainers of this project did not agree that this issue is a vulnerability and considered it a     bug.(CVE-2026-11979)

Tenable has extracted the preceding description block directly from the EulerOS libxml2 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-2026-612470 advisory.

    - Fix CVE-2026-11979 (RHEL-215568)

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 MiracleLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the AXSA:2026-1716:08 advisory.

    * libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free     (CVE-2026-6653)
      * libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow (CVE-2026-11979)

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 AlmaLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2026:61247 advisory.

    * libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free     (CVE-2026-6653)
      * libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow (CVE-2026-11979)

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-2026:61247 advisory.

    * libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free     (CVE-2026-6653)

    * libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow (CVE-2026-11979)

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-2026:61247 advisory.

    The libxml2 library is a development toolbox providing the implementation of various XML standards.

    Security Fix(es):

    * libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free     (CVE-2026-6653)

    * libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow (CVE-2026-11979)

    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 ALAS2023-2026-1911 advisory.

    Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a     remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity     resolution handling. (CVE-2026-6653)

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 version of libxml2 installed on the remote host is prior to 2.9.1-6. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3785 advisory.

    Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a     remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity     resolution handling. (CVE-2026-6653)

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 Ubuntu 22.04 LTS / 24.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-8456-1 advisory.

    Geoffrey Humphreys discovered that libxml2 had a use after free when parsing the internal subset of a DTD.
    A remote attacker could possibly use this issue to cause a denial of service or possibly execute arbitrary     code.

Tenable has extracted the preceding description block directly from the Ubuntu 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 Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a     remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity     resolution handling. (CVE-2026-6653)

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

ID	Name	Product	Family	Type	Severity
347202	EulerOS Virtualization 2.12.1 : libxml2 (EulerOS-SA-2026-3596)	Nessus	Huawei Local Security Checks	Local	high
347071	EulerOS Virtualization 2.12.0 : libxml2 (EulerOS-SA-2026-3650)	Nessus	Huawei Local Security Checks	Local	high
343694	EulerOS 2.0 SP12 : libxml2 (EulerOS-SA-2026-3281)	Nessus	Huawei Local Security Checks	Local	high
343659	EulerOS 2.0 SP12 : libxml2 (EulerOS-SA-2026-3356)	Nessus	Huawei Local Security Checks	Local	high
342293	Oracle Linux 9 : ELSA-2026-61247-0: / libxml2 (ELSA-2026-612470)	Nessus	Oracle Linux Local Security Checks	Local	high
342159	MiracleLinux 9 : libxml2-2.9.13-14.el9_8.4 (AXSA:2026-1716:08)	Nessus	Miracle Linux Local Security Checks	Local	high
341739	AlmaLinux 9 : libxml2 (ALSA-2026:61247)	Nessus	Alma Linux Local Security Checks	Local	high
341687	RockyLinux 9 : libxml2 (RLSA-2026:61247)	Nessus	Rocky Linux Local Security Checks	Local	high
341621	RHEL 9 : libxml2 (RHSA-2026:61247)	Nessus	Red Hat Local Security Checks	Local	high
327405	Amazon Linux 2023 : libxml2, libxml2-devel, libxml2-static (ALAS2023-2026-1911)	Nessus	Amazon Linux Local Security Checks	Local	high
325587	Amazon Linux 2 : libxml2, --advisory ALAS2-2026-3785 (ALAS-2026-3785)	Nessus	Amazon Linux Local Security Checks	Local	high
322479	Ubuntu 22.04 LTS / 24.04 LTS : libxml2 vulnerability (USN-8456-1)	Nessus	Ubuntu Local Security Checks	Local	high
321971	Linux Distros Unpatched Vulnerability : CVE-2026-6653	Nessus	Misc.	Local	high

Detections

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CVE-2026-6653

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Tenable Plugins

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