# CVE-2025-52891: modsecurity-apache: ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx

CVE-2025-52891 is fixed in 6 products on 1 platform, first by DEBIAN-CVE-2025-52891, released July 2, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-52891
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0038
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 2, 2025

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | mod_security amzn 2023 | 2.9.11-1.amzn2023.0.1 | [ALAS2023-2025-1139](https://patchblox.com/security/data/fix/linux/alas2023-2025-1139.md) | Aug 5, 2025 |
| Linux | mod_security-debuginfo amzn 2023 | 2.9.11-1.amzn2023.0.1 | [ALAS2023-2025-1139](https://patchblox.com/security/data/fix/linux/alas2023-2025-1139.md) | Aug 5, 2025 |
| Linux | mod_security-debugsource amzn 2023 | 2.9.11-1.amzn2023.0.1 | [ALAS2023-2025-1139](https://patchblox.com/security/data/fix/linux/alas2023-2025-1139.md) | Aug 5, 2025 |
| Linux | mod_security-mlogc amzn 2023 | 2.9.11-1.amzn2023.0.1 | [ALAS2023-2025-1139](https://patchblox.com/security/data/fix/linux/alas2023-2025-1139.md) | Aug 5, 2025 |
| Linux | mod_security-mlogc-debuginfo amzn 2023 | 2.9.11-1.amzn2023.0.1 | [ALAS2023-2025-1139](https://patchblox.com/security/data/fix/linux/alas2023-2025-1139.md) | Aug 5, 2025 |
| Linux | modsecurity-apache Debian 13.5 (trixie) | 2.9.11-1 | [DEBIAN-CVE-2025-52891](https://patchblox.com/security/data/fix/linux/debian-cve-2025-52891.md) | Jul 2, 2025 |
| Linux | modsecurity-apache Debian 14 | 2.9.11-1 | [DEBIAN-CVE-2025-52891](https://patchblox.com/security/data/fix/linux/debian-cve-2025-52891.md) | Jul 2, 2025 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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