Vulnerability in Oauth2-Proxy
CVE-2026-34454
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
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (12.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Oauth2-Proxy — versions >= 7.11.0, < 7.15.2
- Oauth2 Proxy Project
Weakness classification (CWE)
References
- github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-f24x-5g9q-753f (Release Notes)
- github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34454?
- CVE-2026-34454 is a low-severity vulnerability in Oauth2-Proxy, classified under Session Fixation. CVSS score: 3.5/10. Published 2026-04-14.
- How severe is CVE-2026-34454?
- Low severity. CVSS v3 base score is 3.5 out of 10.