ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one XML tag is empty (eg <foo></foo>), then a segmentation fault occurs. This issue has been patched in version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-993341 advisory.

    ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and     Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If     SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one     XML tag is empty (eg <foo></foo>), then a segmentation fault occurs. This issue has been patched in     version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off.

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.

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2025:0553 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2025-52891:
    ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and     Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If     SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one     XML tag is empty (eg <foo></foo>), then a segmentation fault occurs. This issue has been patched in     version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off.

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

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

  - ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and     Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If     SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one     XML tag is empty (eg <foo></foo>), then a segmentation fault occurs. This issue has been patched in     version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off. (CVE-2025-52891)

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

The version of mod_security installed on the remote host is prior to 2.9.11-1. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2025-2963 advisory.

    ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and     Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If     SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one     XML tag is empty (eg <foo></foo>), then a segmentation fault occurs. This issue has been patched in     version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off. (CVE-2025-52891)

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 ALAS2023-2025-1139 advisory.

    ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and     Nginx. In versions 2.9.8 to before 2.9.11, an empty XML tag can cause a segmentation fault. If     SecParseXmlIntoArgs is set to On or OnlyArgs, and the request type is application/xml, and at least one     XML tag is empty (eg <foo></foo>), then a segmentation fault occurs. This issue has been patched in     version 2.9.11. A workaround involves setting SecParseXmlIntoArgs to Off. (CVE-2025-52891)

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 FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the c0f3f54c-5bc4-11f0-834f-b42e991fc52e advisory.

    security-advisories@github.com reports:
    ModSecurity is an open source, cross platform web application             firewall (WAF) engine for Apache, IIS and Nginx.  In versions 2.9.8             to before 2.9.11, an empty XML tag can cause a segmentation fault.
            If SecParseXmlIntoArgs is set to On or OnlyArgs, and the request             type is application/xml, and at least one XML tag is empty (eg             <foo></foo>), then a segmentation fault occurs.  This             issue has been patched in version 2.9.11.  A workaround involves             setting SecParseXmlIntoArgs to Off.

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

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

ID	Name	Product	Family	Severity
281327	Unity Linux 20.1070e Security Update: mod_security (UTSA-2025-993341)	Nessus	Unity Linux Local Security Checks	medium
253505	TencentOS Server 4: mod_security (TSSA-2025:0553)	Nessus	Tencent Local Security Checks	medium
252711	Linux Distros Unpatched Vulnerability : CVE-2025-52891	Nessus	Misc.	medium
252310	Amazon Linux 2 : mod_security (ALAS-2025-2963)	Nessus	Amazon Linux Local Security Checks	medium
251376	Amazon Linux 2023 : mod_security, mod_security-mlogc (ALAS2023-2025-1139)	Nessus	Amazon Linux Local Security Checks	medium
241648	FreeBSD : ModSecurity -- empty XML tag causes segmentation fault (c0f3f54c-5bc4-11f0-834f-b42e991fc52e)	Nessus	FreeBSD Local Security Checks	medium

Detections

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CVE-2025-52891

medium

Tenable Plugins

medium

medium

medium

medium

medium

medium