Authentication bypass via access-token-only OIDC callbacks
Published Aug 29, 2026 · Updated Aug 29, 2026
Authentication bypass in pac4j-oidc before 6.5.6 allows remote attackers to create sessions using tokens issued to other clients. OidcCredentialsExtractor accepts a callback when an access token is present even if both the authorization code and ID token are absent. An attacker needs a token minted for another client; issuer, audience, nonce, and subject checks are then bypassed when the host creates the session.
Summary
What happened
Authentication bypass in pac4j-oidc before 6.5.6 allows remote attackers to create sessions using tokens issued to other clients. OidcCredentialsExtractor accepts a callback when an access token is present even if both the authorization code and ID token are absent. An attacker needs a token minted for another client; issuer, audience, nonce, and subject checks are then bypassed when the host creates the session.
The record
- CVE
- CVE-2026-82462
- Published
- Aug 29, 2026
- Updated
- Aug 29, 2026
- Vendor
- pac4j
- Product
- pac4j
- Classifications
- CWE-345, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 29, 2026CVE publishedPublication date reported by the CVE source.
- Aug 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.5.6
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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