Is there a public exploit for CVE-2026-104259?

No public exploit for CVE-2026-104259 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-104259?

CVE-2026-104259 scores CVSS 5.4 (v3.1), rated medium.

What does CVE-2026-104259 affect?

CVE-2026-104259 affects owasp-modsecurity ModSecurity.

5.4 Medium

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx.

CVE-2026-104259

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 2.9.15 and 3.0.17, msrefnremoveCommentsexecute in apache2/retfns.c and inplace() in src/actions/transformations/removecomments.cc implement t:removeComments by copying the character immediately after a comment terminator without re-evaluating it. Adjacent comments can therefore leave a later comment in the transformed value, allowing inline-comment obfuscation to bypass rules that depend on comment stripping. When a comment terminator is the final content, the same copy reads one byte beyond the input buffer. This issue is fixed in versions 2.9.15 and 3.0.17.

Assessment

CVSS: 5.4 (v3.1)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 9 November 2026
Last updated: 9 November 2026
Affected: owasp-modsecurity · ModSecurity
Assigner: GitHub_M

CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

At the source

EUVD (ENISA)

References

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