CVE-2026-61812: ModSecurity · Improper Encoding or Decoding of Data
Affects ModSecuritySource CVE Database V5
Not known to be exploited · CVSS 6.3 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 4.0 | 6.3 |
|---|
- Patch
- Available – fixed in 3.0.17, 2.9.15
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA: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, or 3.0.17 or later, where this vulnerability has been fixed. No other mitigation is required as the issue is resolved in these versions.
Description
CVE-2026-61812 affects ModSecurity, an open source web application firewall engine. Versions prior to 2.9.15 and between 3.0.0 and before 3.0.17 have an improper encoding/decoding issue in the t:htmlEntityDecode function. This function recognizes only a limited set of named HTML entities, causing discrepancies between ModSecurity's transformations and those of browsers or backends. Attackers can exploit this by encoding ASCII separators and operators with unhandled or alias entity names to bypass security rules. The vulnerability is fixed in versions 2.9.15 and 3.0.17.
References
- github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-cxqf-vgrr-xxrv (opens in a new tab)
- github.com/owasp-modsecurity/ModSecurity/commit/6353be7b09ff222d29a7491c26307d293b00d56f (opens in a new tab)
- github.com/owasp-modsecurity/ModSecurity/commit/77be8039d734d36ec291d8fbda9e69326ae44755 (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)