5.8

CVE-2026-41508: OWASP Coraza WAF: Truncated multipart body bypasses MULTIPART_STRICT_ERROR (rule 200003) via silent io.ErrUnexpectedEOF handling

Deferred
AliasesGHSA-r3rm-qphw-hh76GO-2026-6670
Published 12-10-2026Last modified 13-10-2026

Vulnerability summary

CVE-2026-41508 is a medium (CVSS 5.8) Protection Mechanism Failure vulnerability in corazawaf coraza. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 42.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.8, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.8/10
010
Medium · v3.1 (NVD)
EPSS score
0.50%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 12-10-2026
    PublishedVulnerability first disclosed.
  2. 13-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.50%

Chance of exploitation in the next 30 days

Percentile

43%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

13-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Github.com/corazawaf/coraza2 products
  • v2All versions (No fix recorded)
  • v3≥ 3.4.0, < 3.8.0
Corazawaf1 product
Github.com/corazawaf1 product
  • corazaAll versions (No fix recorded)

3 vendors · 4 products

References

4 links