{"id":"CVE-2026-34454","aliases":["BIT-oauth2-proxy-2026-34454","GHSA-f24x-5g9q-753f","GO-2026-5341"],"url":"https://o3.security/vulnerability/CVE-2026-34454","summary":"OAuth2 Proxy: Session cookie not cleared when rendering sign-in page","details":"### Impact\nA 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.\n\nThis 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.\n\nDeployments that use a dedicated logout/sign-out endpoint to terminate sessions are not affected.\n\n### Patches\nThis issue is fixed in v7.15.2.\n\n### Workarounds\nDo not rely on the sign-in page to clear an existing session. Instead:\n\n- Use the dedicated logout/sign-out endpoint of OAuth2 Proxy\n- Ensure your application logout flow explicitly clears the OAuth2 Proxy   session cookie before redirecting users to the sign-in page\n- If needed, clear the session cookie at the reverse proxy or application   layer as a temporary mitigation","published":"2026-04-14T22:10:37.901Z","modified":"2026-10-28T02:30:24.620919754Z","cvss":{"score":3.5,"severity":"LOW","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"},"epss":{"score":0.00183,"percentile":0.08117,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/oauth2-proxy/oauth2-proxy/v7","fixedVersion":"7.15.2"}],"fix":{"url":"https://github.com/oauth2-proxy/oauth2-proxy/pull/2605","label":"oauth2-proxy/oauth2-proxy#2605"},"references":[{"type":"WEB","url":"https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34454.json"},{"type":"ADVISORY","url":"https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-f24x-5g9q-753f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34454"},{"type":"WEB","url":"https://github.com/oauth2-proxy/oauth2-proxy/pull/2605"},{"type":"PACKAGE","url":"https://github.com/oauth2-proxy/oauth2-proxy"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:24.620919754Z"}}