Vulnerability · Published Oct 26, 2026 · Assigned by GitHub_M
CVE-2026-115910Python Social Auth: OpenID Connect nonce is not bound to the browser session, so a stolen authorization code logs the attacker in as the victim
Medium 6.8
In plain English
A medium-severity insufficient verification of data authenticity in social-core from python-social-auth. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | social-auth-core | no fix listed | DEBIAN-CVE-2026-115910 |
| Debian:13 | social-auth-core | no fix listed | DEBIAN-CVE-2026-115910 |
| Debian:14 | social-auth-core | no fix listed | DEBIAN-CVE-2026-115910 |
| PyPI | social-auth-core | 6.2.0 | GHSA-h2r5-x5m7-3935 |
| Ubuntu:22.04:LTS | social-auth-core | no fix listed | UBUNTU-CVE-2026-115910 |
| Ubuntu:24.04:LTS | social-auth-core | no fix listed | UBUNTU-CVE-2026-115910 |
| Ubuntu:26.04:LTS | social-auth-core | no fix listed | UBUNTU-CVE-2026-115910 |
| Ubuntu:26.10 | social-auth-core | no fix listed | UBUNTU-CVE-2026-115910 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-social-auth | social-core | < 6.2.0 |
Weakness: CWE-345, CWE-384 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
References
- https://github.com/python-social-auth/social-core/security/advisories/GHSA-h2r5-x5m7-3935 x_refsource_CONFIRM
- https://github.com/python-social-auth/social-core/pull/2141 x_refsource_MISC
- https://github.com/python-social-auth/social-core/commit/c2f2ae4663bef19ee8b07f2cf5a2344f9155d826 x_refsource_MISC
- https://github.com/python-social-auth/social-core/releases/tag/6.2.0 x_refsource_MISC