CVE-2026-34454
LOW3.5EPSS 0.01%OAuth2 Proxy's session cookies are not cleared when rendering sign-in page
Description
### Impact A regression introduced in [v7.11.0](https://github.com/oauth2-proxy/oauth2-proxy/pull/2605) 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. ### Patches This issue is fixed in v7.15.2. ### 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
Affected packages (2)
- Bitnami/oauth2-proxy>= 7.11.0, < 7.15.2
- Go/github.com/oauth2-proxy/oauth2-proxy/v7>= 7.11.0, < 7.15.2
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.5 | CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N |
References (5)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-34454
- PATCHhttps://github.com/oauth2-proxy/oauth2-proxy
- WEBhttps://github.com/oauth2-proxy/oauth2-proxy/pull/2605
- WEBhttps://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2
- WEBhttps://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-f24x-5g9q-753f