Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, OpenIDMixin.parse_id_token() reads the nonce_supported decision from the untrusted ID token being validated and sets the expected nonce to null when that claim is the JSON boolean false. In implicit and hybrid relying parties, or applications that directly accept externally supplied ID tokens, an attacker with a captured validly signed token can bypass the nonce-to-session binding and replay the victim's token into an attacker-controlled session. Plain authorization code flow is not affected, and the token must still pass signature, issuer, and audience validation. OpenIDMixin.parse_id_token() trusts nonce_supported in both authlib/integrations/base_client/sync_openid.py and authlib/integrations/base_client/async_openid.py to disable the expected nonce. This issue is fixed in version 1.9.0.
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History
Fri, 23 Oct 2026 03:45:00 +0000
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Authlib
Authlib authlib |
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Authlib
Authlib authlib |
Fri, 23 Oct 2026 00:45:00 +0000
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| Description | Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, OpenIDMixin.parse_id_token() reads the nonce_supported decision from the untrusted ID token being validated and sets the expected nonce to null when that claim is the JSON boolean false. In implicit and hybrid relying parties, or applications that directly accept externally supplied ID tokens, an attacker with a captured validly signed token can bypass the nonce-to-session binding and replay the victim's token into an attacker-controlled session. Plain authorization code flow is not affected, and the token must still pass signature, issuer, and audience validation. OpenIDMixin.parse_id_token() trusts nonce_supported in both authlib/integrations/base_client/sync_openid.py and authlib/integrations/base_client/async_openid.py to disable the expected nonce. This issue is fixed in version 1.9.0. | |
| Title | Authlib: ID token can disable its own nonce validation via the nonce_supported claim | |
| Weaknesses | CWE-294 CWE-807 |
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| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-10-22T21:25:31.732Z
Reserved: 2026-10-21T20:34:25.600Z
Link: CVE-2026-114617
No data.
Status : Received
Published: 2026-10-22T22:18:04.580
Modified: 2026-10-22T22:18:04.580
Link: CVE-2026-114617
No data.
OpenCVE Enrichment
Updated: 2026-10-23T03:45:16Z