CVE-2026-104259: ModSecurity · Always-Incorrect Control Flow Implementation
Affects ModSecuritySource CVE Database V5
Not known to be exploited · CVSS 5.4 Medium : upgrade to 3.0.17 or 2.9.15 when convenient.
Data as of 9 Nov 2026, 21:49 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.4 |
|---|
- Patch
- Available – fixed in 3.0.17, 2.9.15
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 9 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade ModSecurity to 3.0.17 or 2.9.15.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| owasp-modsecurityModSecurity | Affected
| Fixed in
|
| owasp-modsecurityModSecurity | Affected
| Fixed in
|
AI-suggested
Upgrade ModSecurity to version 2.9.15 or later in the 2.9.x series, or to version 3.0.17 or later in the 3.0.x series. These versions contain the official fix for this vulnerability. No other mitigation is required as the issue is resolved in these releases.
Description
CVE-2026-104259 is a vulnerability in ModSecurity, an open source web application firewall. Versions prior to 2.9.15 and between 3.0.0 and before 3.0.17 improperly handle comment removal in certain functions, allowing inline-comment obfuscation to bypass security rules. Additionally, when a comment terminator is at the end of input, the code reads beyond the input buffer, causing a potential out-of-bounds read. This issue is fixed in versions 2.9.15 and 3.0.17.
References
- github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-qrch-pjfr-9g47 (opens in a new tab)
- github.com/owasp-modsecurity/ModSecurity/commit/264f348ae1823cb71cead3650b74c165678a1d46 (opens in a new tab)
- github.com/owasp-modsecurity/ModSecurity/commit/49a65f471d3130b91f7fff9bfac9fe8dd9b97c44 (opens in a new tab)
- github.com/owasp-modsecurity/ModSecurity/releases/tag/v2.9.15 (opens in a new tab)
- github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.17 (opens in a new tab)