CVE-2026-42560
A critical flaw in the auth library used for Patreon OAuth causes all Patreon users to be treated as the same local account. This happens because the library incorrectly assigns the same local user ID to every authenticated Patreon account. As a result, users can inadvertently access each other's data or subscriptions.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Applications that use the auth library for Patreon OAuth, specifically versions 1.18.0 through 1.25.1 and 2.0.0 through 2.1.1, are affected. Developers and site owners who rely on this library for user authentication should check their version.
Real-world impact
An attacker could gain access to another user's account, view or modify their subscription status, and potentially confuse or elevate privileges by exploiting the collapsed identity.
Why this severity
The CVSS score of 9.1 reflects that the vulnerability is exploitable over the network without authentication, provides complete confidentiality and integrity compromise for affected users, and has no mitigations in place. The lack of required privileges and the high impact on user data make it critical.
What to do about it
- 01Upgrade the auth library to version 1.25.2 or later, or to version 2.1.2 or later.
NVD-referenced vendor advisory
Timeline
- May 9, 2026 · May 9, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 24, 2026 · 11d agoAdvisory updatedThe NVD record was last revised.
- Jul 26, 2026 · 10d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.