CVE-2026-30923
libModSecurity3 denial of service via segfault when using t:hexDecode on single-character query strings
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 3.0.15
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: poc
- Automatable: yes
- Technical impact: partial
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- owasp-modsecurity ModSecurity
fixed in 3.0.15