9.3 CriticalCWE-794
CVE-2026-21876
coreruleset vulnerability
Status
- Not in CISA KEV
- Vendor fix available
Exploit probabilityEPSSchecked 25 Oct
18%probability of exploitation in the next 30 days
Higher than 97% of scored CVEs
SeverityCVSS
9.3Critical
Description NVD
The OWASP core rule set (CRS) is a set of generic attack detection rules for use with compatible web application firewalls. Prior to versions 4.22.0 and 3.3.8, the current rule 922110 has a bug when processing multipart requests with multiple parts. When the first rule in a chain iterates over a collection (like `MULTIPART_PART_HEADERS`), the capture variables (`TX:0`, `TX:1`) get overwritten with each iteration. Only the last captured value is available to the chained rule, which means malicious charsets in earlier parts can be missed if a later part has a legitimate charset. Versions 4.22.0 and 3.3.8 patch the issue.
Coverage No articles yet
No CyberSIXT article names CVE-2026-21876 yet. New articles appear here and in the RSS feed.