CVE-2026-34454: OAUTH2 Proxy Project OAUTH2 Proxy

Low severity, CVSS 3.5. EPSS: 0.2% chance of exploitation in the next 30 days.

OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. A regression introduced in 7.11.0 prevents OAuth2 Proxy from clearing the session cookie when rendering the sign-in page. In deployments that rely on the sign-in page as part of their logout flow, a user may be shown the sign-in page while the existing session cookie remains valid, meaning the browser session is not actually logged out. On shared workstations or devices, a subsequent user could continue to use the previous user's authenticated session. Deployments that use a dedicated logout/sign-out endpoint to terminate sessions are not affected. This issue is fixed in 7.15.2

Affected products

• OAUTH2 Proxy Project OAUTH2 Proxy: from 7.11.0, before 7.15.2 (fixed in 7.15.2)

Published 2026-04-14. Last modified 2026-07-24.