What’s Vulnerable › Vulnerabilities

CVE-2026-34454: OAuth2 Proxy: Session cookie not cleared when rendering sign-in page

• Severity: low (CVSS 3.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-14 · updated 2026-07-24
• Weakness: CWE-384

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

Affected products

• oauth2-proxy: from 7.11.0 before 7.15.2 — fixed in 7.15.2

How to fix

Upgrade to a fixed version: oauth2-proxy 7.15.2. Check the vendor advisory for mitigations.

References

• https://github.com/oauth2-proxy/oauth2-proxy/releases/tag/v7.15.2
• https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-f24x-5g9q-753f

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