CVE-2025-52891: ModSecurity empty XML tag causes segmentation fault

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-02 · updated 2026-06-17
Weakness: CWE-20

Description

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.

Affected products

owasp-modsecurity ModSecurity: from 2.9.8, < 2.9.11

References

https://github.com/owasp-modsecurity/ModSecurity/commit/ecd7b9736836eee391d25f35d5bd06a3ce35a45d
https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-gw9c-4wfm-vj3x

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