CVE-2026-34454

Workarounds

Do not rely on the sign-in page to clear an existing session. Instead:

• Use the dedicated logout/sign-out endpoint of OAuth2 Proxy
• Ensure your application logout flow explicitly clears the OAuth2 Proxy session cookie before redirecting users to the sign-in page
• If needed, clear the session cookie at the reverse proxy or application layer as a temporary mitigation

A regression introduced in v7.11.0 is preventing OAuth2 Proxy from clearing the session cookie when rendering the sign-in page.

This only impacts deployments that rely on the sign-in page as part of their logout flow. In those setups, a user may be shown the sign-in page while the existing session cookie remains valid, so the browser session is not actually logged out. On shared workstations be it browsers 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.

CVE-2026-34454 has a CVSS score of 3.5 (Low). The vector is requires physical access, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (7.15.2); upgrading removes the vulnerable code path.

Kodem intelligence

This issue is fixed in v7.15.2.

1. What is CVE-2026-34454? CVE-2026-34454 is a low-severity security vulnerability in github.com/oauth2-proxy/oauth2-proxy/v7 (go), affecting versions >= 7.11.0, < 7.15.2. It is fixed in 7.15.2.
2. How severe is CVE-2026-34454? CVE-2026-34454 has a CVSS score of 3.5 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/oauth2-proxy/oauth2-proxy/v7 are affected by CVE-2026-34454? github.com/oauth2-proxy/oauth2-proxy/v7 (go) versions >= 7.11.0, < 7.15.2 is affected.
4. Is there a fix for CVE-2026-34454? Yes. CVE-2026-34454 is fixed in 7.15.2. Upgrade to this version or later.
5. Is CVE-2026-34454 exploitable, and should I be worried? Whether CVE-2026-34454 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-34454 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-34454? Upgrade github.com/oauth2-proxy/oauth2-proxy/v7 to 7.15.2 or later.