CVE-2026-41508
Coraza: Truncated multipart body bypasses MULTIPART_STRICT_ERROR (rule 200003) via silent io.ErrUnexpectedEOF handling
Impact
OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. From 3.4.0 until 3.8.0, the multipart processor in internal/bodyprocessors/multipart.go treats io.ErrUnexpectedEOF as nonfatal without setting MULTIPART_STRICT_ERROR. A remote attacker can submit a truncated multipart body that produces io.ErrUnexpectedEOF, causing parsing to stop without raising the strict-error signal used by the recommended defensive rule. Rules 200002 and 200003 do not fire, allowing multipart parser-disagreement payloads to reach a backend that interprets the truncated body differently. This issue is fixed in version 3.8.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/corazawaf/coraza/v3 | >= 3.4.0, <= 3.7.0 | 3.8.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-r3rm-qphw-hh76
- https://github.com/corazawaf/coraza/security/advisories/GHSA-r3rm-qphw-hh76
- https://github.com/corazawaf/coraza/commit/f94c81bec209f658120c418448d0590a549b71df
- https://github.com/corazawaf/coraza/releases/tag/v3.8.0