Authorization code injection via missing c_hash validation
Published Aug 6, 2026 · Updated Aug 6, 2026
Improper input validation in Apache CXF OIDC relying parties allows remote attackers to inject authorization codes during Hybrid Flow. The relying-party Hybrid Flow accepts an authorization response when c_hash is absent, so the received code is not cryptographically bound to the ID token. Exploitation requires a non-compliant or misconfigured identity provider that omits c_hash; successful substitution makes the relying party process an attacker-selected authorization code.
Summary
What happened
Improper input validation in Apache CXF OIDC relying parties allows remote attackers to inject authorization codes during Hybrid Flow. The relying-party Hybrid Flow accepts an authorization response when c_hash is absent, so the received code is not cryptographically bound to the ID token. Exploitation requires a non-compliant or misconfigured identity provider that omits c_hash; successful substitution makes the relying party process an attacker-selected authorization code.
The record
- CVE
- CVE-2026-57817
- Published
- Aug 6, 2026
- Updated
- Aug 6, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache CXF
- Classifications
- CWE-20
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 6, 2026CVE publishedPublication date reported by the CVE source.
- Aug 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Is a vulnerable build present?
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- Affected versionversion=0 <3.6.12
- Affected versionversion=4.0.0 <4.1.8
- Affected versionversion=4.2.0 <4.2.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
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Your stack
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