Skip to content
Fencer Intel
medium 6.5

CVE-2025-52891 json

ModSecurity empty XML tag causes segmentation fault

published last yr. modified 4mo ago also BIT-modsecurity-2025-52891 , BIT-modsecurity2-2025-52891 , EUVD-2025-19726 , GHSA-gw9c-4wfm-vj3x

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami modsecurity 3.0.12
  • bitnami modsecurity2 2.9.11
  • owasp libmodsecurity 2.9.11
  • owasp modsecurity 2.9.11
  • owasp owasp_modsecurity 2.9.11
  • trustwave modsecurity 2.9.11
  • modsecurity-apache Debian 14, Debian 13 2.9.11-1

debian advisories DEBIAN-CVE-2025-52891

  • apache2-mod_security2 openSUSE Tumbleweed 2.9.11-1.1

opensuse advisories openSUSE-SU-2025:15313-1

Is CVE-2025-52891 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-52891 updated cvss 4.3

mod_security: ModSecurity segmentation fault

  • Red Hat Enterprise Linux 7 mod_security, mod_security-mlogc Red Hat Enterprise Linux 8 mod_security, mod_security-mlogc Red Hat Enterprise Linux 9 mod_security, mod_security-mlogc Red Hat JBoss Core Services mod_security, jbcs-httpd24-mod_security, jbcs-httpd24-mod_security-src-zip
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami modsecurity
>=2.9.8, <3.0.12
3.0.12
bitnami modsecurity2
>=2.9.8, <2.9.11
2.9.11

Affected products

  • owasp-modsecurity ModSecurity

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.