CVE-2026-62322: Python Social Auth: Login CSRF in LINE backend (LineOAuth2) — missing OAuth state validation (incomplete fix of 5.0.0 campaign)

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-15 · updated 2026-10-28
Weakness: CWE-352

Description

Python Social Auth is a social authentication/registration mechanism. Prior to 5.0.2, the LINE backend exchanges an authorization code without validating the returned OAuth state. An attacker can begin authorization for an attacker-controlled LINE account and induce a victim to visit the resulting callback URL, causing the application to log the victim into the attacker's account. When account linking is enabled, the same missing validation can link the attacker's LINE identity to the victim's existing account and create a persistent unauthorized login path. Only applications with the LINE backend enabled are affected. This issue is fixed in version 5.0.2.

Affected products

python-social-auth social-core: before 5.0.2

References

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