CVE-2026-30923
An attacker can exploit this to crash worker processes, causing a denial of service.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.43%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.43% probability · 37th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- owasp/modsecurity
- Source
- security-advisories@github.com
References
- https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.15Patch, Product
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-qrjc-3jpc-3h2gExploit, Vendor Advisory
- https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-qrjc-3jpc-3h2gExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.