CVE-2026-73856

NameCVE-2026-73856
DescriptionModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.0 until 3.0.17, src/transaction.cc compares a response Content-Type value against SecResponseBodyMimeType entries case-sensitively. A mixed-case response media type that is semantically equivalent to a configured lowercase type can therefore be treated as unconfigured, causing ModSecurity to skip RESPONSE_BODY inspection. An unauthenticated requester can then receive response content that a phase 4 rule would otherwise block, including sensitive error or debug data. This issue is fixed in version 3.0.17.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1149651

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
modsecurity (PTS)bookworm3.0.9-1+deb12u2vulnerable
trixie3.0.14-1+deb13u1vulnerable
forky, sid3.0.16-1vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
modsecuritysource(unstable)(unfixed)1149651

Notes

https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-vmg8-j66p-vgvw
https://modsecurity.org/20260928/security-update-digest-overview-of-recent-advisory-fixes-2026-september/

Search for package or bug name: Reporting problems