Improper input validation in Apache Cxf
CVE-2026-57817
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.004 (38.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Apache Cxf
- Apache Software Foundation Cxf — versions 4.2.0, 4.0.0, 0
Weakness classification (CWE)
References
- security@apache.org (vendor-advisory, Mailing List, Vendor Advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2026-57817?
- CVE-2026-57817 is a high-severity vulnerability in Apache Cxf, classified under Improper Input Validation. CVSS score: 8.1/10. Published 2026-08-06.
- How severe is CVE-2026-57817?
- High severity. CVSS v3 base score is 8.1 out of 10.