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

Published Aug 6, 2026
·
Updated

The OpenID Connect Core 1.0 specification mandates that the RP MUST validate the chash 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 chash, 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 Software

1 affected component
Apache CXF>3.6.11<4.1.7, >4.1.7<4.2.2, >4.2.2<4.2.3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Apache CXF to a version that resolves this vulnerability.

    Fixed in 4.2.3
  2. Upgrade

    Upgrade Apache CXF to a version that resolves this vulnerability.

    Fixed in 4.1.8
  3. Upgrade

    Upgrade Apache CXF to a version that resolves this vulnerability.

    Fixed in 3.6.12

Event History

Aug 6, 2026
CVE Published
via MITRE·10:24 AM
Data Sourced
via MITRE·10:24 AM
DescriptionWeakness
Data Sourced
via NVD·11:16 AM
DescriptionWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2026-57817?

CVE-2026-57817 has a risk score of 55, indicating a medium severity vulnerability.

2

How do I fix CVE-2026-57817?

To fix CVE-2026-57817, ensure that your Apache CXF RP is integrated with a compliant Identity Provider that validates the c_hash parameter in the Hybrid OIDC flow.

3

What systems are affected by CVE-2026-57817?

CVE-2026-57817 affects Apache CXF implementations that utilize the Hybrid OIDC flow without proper validation of the c_hash parameter.

4

What is the impact of CVE-2026-57817?

The impact of CVE-2026-57817 includes potential authorization code misuse and elevated security risks due to the lack of c_hash validation.

5

Is there a workaround for CVE-2026-57817?

Currently, the best workaround for CVE-2026-57817 is to configure your Identity Provider to enforce the c_hash parameter validation.

Company

Resources

Contact

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