Description
Python Social Auth is a social authentication and registration mechanism. Prior to 6.2.0, OpenIdConnectAuth in social_core/backends/open_id_connect.py uses get_and_store_nonce to place the OpenID Connect nonce in a shared OpenIdConnectAssociation table, and get_nonce and validate_claims verify only that the nonce exists and has not expired rather than binding it to the browser session and OAuth state that initiated the login. An attacker who obtains a victim's unused authorization code can start a separate login to obtain valid state for the attacker's browser, submit the victim's code with that state, and pass nonce validation because the victim nonce is globally available. With DEFAULT_USE_PKCE disabled in the default OpenIdConnectAuth configuration, the attacker can be logged in as the victim. This issue is fixed in version 6.2.0.
References5
- github.com/python-social-auth/social-core/commit/c2f2ae4663bef1…
- github.com/python-social-auth/social-core/pull/2141
- github.com/python-social-auth/social-core/releases/tag/6.2.0
- github.com/python-social-auth/social-core/security/advisories/G…
- github.com/python-social-auth/social-core/security/advisories/G…
Metrics
- CVSS 3.1
-
6.8
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 5 · as of 8 November 2026
- CWE
- CWE-345CWE-384
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