CVE-2026-34454 OAuth2 Proxy: Session cookie not cleared when rendering sign-in page
Attackers on shared devices can hijack sessions because the proxy fails to clear cookies during sign-in page rendering, requiring specific logout flow configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34454?
CVE-2026-34454 is a low-severity authentication bypass vulnerability in oauth2-proxy, published on 14 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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
Which versions are affected by CVE-2026-34454?
5 open source packages ship an affected version, including github.com/oauth2-proxy/oauth2-proxy/v7, oauth2-proxy and github.com/oauth2-proxy/oauth2-proxy. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/oauth2-proxy/oauth2-proxy/v7 Go | From 7.11.0 | 7.15.2 |
github.com/oauth2-proxy/oauth2-proxy/v7 Go | From 7.11.0 | 7.15.2 |
github.com/oauth2-proxy/oauth2-proxy/v7 Go | From 7.11.0 | 7.15.2 |
oauth2-proxy Bitnami | From 7.11.0 | 7.15.2 |
github.com/oauth2-proxy/oauth2-proxy Go | All versions | None |
Products include Oauth2 Proxy Project Oauth2 Proxy.
How do I fix CVE-2026-34454?
Upgrade github.com/oauth2-proxy/oauth2-proxy/v7 to 7.15.2 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-34454 being exploited?
There is no known exploitation of CVE-2026-34454 in the wild and no public exploit code.
Other vulnerabilities in oauth2-proxy
- CVE-2026-40575 OAuth2 Proxy has an Authentication Bypass via X-Forwarded-Uri Header Spoofing
- CVE-2026-34457 OAuth2 Proxy: Health Check User-Agent Matching Bypasses Authentication in auth_request Mode
- CVE-2025-54576 OAuth2-Proxy has authentication bypass in oauth2-proxy skip_auth_routes due to Query Parameter inclusion
- CVE-2017-1000069 Cross-site Request Forgery (CSRF)
- CVE-2026-41059 OAuth2 Proxy has an Authentication Bypass via Fragment Confusion in skip_auth_routes and skip_auth_regex
Sources
Also known as BIT-oauth2-proxy-2026-34454, GHSA-f24x-5g9q-753f, GO-2026-5341, MINI-m8xg-wgh8-86m2, MINI-wcv9-4mcj-w659.