Bug 2466843 (CVE-2026-30923) - CVE-2026-30923 libModSecurity3: ModSecurity: ModSecurity: Denial of Service via crafted query string parameter in t:hexDecode transformation
Summary: CVE-2026-30923 libModSecurity3: ModSecurity: ModSecurity: Denial of Service v...
Keywords:
Status: NEW
Alias: CVE-2026-30923
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
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Depends On: 2484694 2484697 2484698 2484699 2484700 2484701
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-05-05 19:01 UTC by OSIDB Bzimport
Modified: 2026-06-04 10:19 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-05-05 19:01:35 UTC 
ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Libmodsecurity is one component of the ModSecurity v3 project. A segmentation fault occurs when a rule using the t:hexDecode transformation inspects a query string parameter containing a single character. An attacker can exploit this to crash worker processes, causing a denial of service. Service resumes once the attack stops as worker processes recover from the segfault. All versions before 3.0.15 of libModSecurity3 are affected. This has been patched in version 3.0.15.
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