Bug 2567505 (CVE-2026-103932)

Summary:	CVE-2026-103932 modsecurity: ModSecurity: Security rule bypass via regular expression limit exhaustion
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in ModSecurity. The regular expression engine improperly handles execution limit errors during pattern matching, treating them as ordinary non-matches instead of error conditions. A remote attacker can exploit this vulnerability by submitting crafted input designed to exceed processing limits, preventing compensating security inspection rules from executing. Consequently, malicious requests that should be rejected may bypass the web application firewall (WAF).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-11-05 22:03:15 UTC

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.5 until 3.0.17, the PCRE2 implementation of @rxGlobal in src/utils/regex.cc converts pcre2_match match-limit errors into an ordinary no-match result instead of propagating a non-OK RegexResult. When attacker-controlled input exhausts SecPcreMatchLimit, rules that rely on MSC_PCRE_LIMITS_EXCEEDED or its TX compatibility indicator do not run, so a request that should be rejected can pass through the WAF. The issue affects PCRE2 deployments that use @rxGlobal with a limit-exhaustible expression and a compensating rule; it is not a universal WAF bypass. This issue is fixed in version 3.0.17.