CVE-2026-34454 PUBLISHED

OAuth2 Proxy: Session cookie not cleared when rendering sign-in page

Assigner: GitHub_M
Reserved: 27.03.2026 Published: 14.04.2026 Updated: 15.04.2026

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

Metrics

CVSS Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS Score: 3.5

Product Status

Vendor oauth2-proxy
Product oauth2-proxy
Versions
  • Version >= 7.11.0, < 7.15.2 is affected

References

Problem Types

  • CWE-613: Insufficient Session Expiration CWE
  • CWE-384: Session Fixation CWE