CVE-2026-57817: Apache Cxf

High severity, CVSS 8.1. EPSS: 0.7% chance of exploitation in the next 30 days.

The OpenID Connect Core 1.0 specification mandates that the RP MUST validate the `c_hash` parameter when operating in the Hybrid Flow. If an Apache CXF RP is integrated with a non-compliant or misconfigured Identity Provider (IdP) that omits the `c_hash`, the RP becomes vulnerable to Authorization Code Substitution/Injection attacks. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.

Affected products

• Apache Cxf: before 3.6.12 (fixed in 3.6.12); from 4.0.0, before 4.1.8 (fixed in 4.1.8); from 4.2.0, before 4.2.3 (fixed in 4.2.3)

Published 2026-08-06. Last modified 2026-08-07.