CVE-2026-61619

CVSS 8.8 (high) · published 2026-11-11

The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls. Prior to versions 3.3.10, 4.25.1, and 4.28.0, regular-expression denial of service (ReDoS) affects a shared regex-assembly include used to build 12 Unix RCE detection rules in CRS v4, and the same ambiguous pattern was present in the manually-assembled regexes in 4 rules in CRS v3.3. With a single, unauthenticated, crafted request, the generated pattern drives PCRE2 past its backtracking limit. When PCRE2 exceeds that limit, the @rx operator returns an error rather than a match result, which results in detection bypass and CPU denial of service. This issue has been patched in versions 3.3.10, 4.25.1, and 4.28.0.

Weakness: CWE-1333

Source: NVD CVE-2026-61619

References

• https://github.com/coreruleset/coreruleset/commit/4665b6d7a79a81aa8a802ef3c901d69491c009a4
• https://github.com/coreruleset/coreruleset/commit/6083611d00291e85ab7b587e96577deb53ed9cac
• https://github.com/coreruleset/coreruleset/commit/e3b612a909532dcc8d056c01ac04b31117b71505
• https://github.com/coreruleset/coreruleset/security/advisories/GHSA-f5qm-3h4p-8qhg

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