CVSS 3.1
8.6 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:NCVE-2026-73856
High (8.6) in owasp-modsecurity modsecurity.
On this page
ModSecurity 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.
Severity
- CWE
- CWE-178 Improper Handling of Case Sensitivity
- Published
- Record from
- the CVE List, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| owasp-modsecurity ModSecurity | >= 3.0.0, < 3.0.17 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 12, 13, 14 | modsecurity | no fix listed | DEBIAN-CVE-2026-73856 |
| Ubuntu | 20.04:LTS, 22.04:LTS, 24.04:LTS and 2 more | modsecurity | no fix listed | UBUNTU-CVE-2026-73856 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.