High 8.1Published Aug 6, 2026

CVE-2026-57817Apache CXF: The authorization code hash (c_hash) is not enforced for the hybrid OIDC flow

Updated under an hour ago (Oct 28, 2026, 11:40 AM ET)

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It affects Apache Software Foundation Apache CXF and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Apache Software Foundation Apache CXF

Exploited in the last 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.

CVSS: 8.1 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-20
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: apache
NVD analysis: Modified
Record last updated: Aug 6, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Apache Software Foundation Apache CXF apache_software_foundation:apache_cxf (from the name)	from 4.2.0 before 4.2.3; from 4.0.0 before 4.1.8; before 3.6.12	CNA record
apache cxf apache:cxf	before 3.6.12; from 4.0.0 before 4.1.8; from 4.2.0 before 4.2.3	NVD

References

References

https://lists.apache.org/thread/pj63c3pf7kkp1xhr53do704fwj3t3htn	vendor-advisory, mailing-list
http://www.openwall.com/lists/oss-security/2026/08/06/19

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.