CVE-2026-34454: OAuth2 Proxy insufficient session expiration in sign-in page handler

CVE-2026-34454 · Severity: low · CVSS 3.5 · Published 2026-04-14

OAuth2 Proxy is a tool used to manage user logins for web applications. A bug in certain versions prevents the software from properly clearing a user's session cookie when they are sent to the sign-in page. On shared computers, this could allow a new user to access the previous person's account because the session was never actually terminated.

Technologies: github.com/oauth2-proxy/oauth2-proxy (Go), github.com/oauth2-proxy/oauth2-proxy/v7 (Go), OAuth2 Proxy. Vendors: Go, OAuth2 Proxy.

Quick answers

Is CVE-2026-34454 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-34454 being exploited in the wild.
How severe is CVE-2026-34454?
Low severity, with a CVSS score of 3.5, published 14 April 2026.
Which products and versions are affected?
github.com/oauth2-proxy/oauth2-proxy (Go) SEMVER:introduced=0; github.com/oauth2-proxy/oauth2-proxy/v7 (Go) >= 7.11.0, < 7.15.2, SEMVER:introduced=7.11.0,fixed=7.15.2; OAuth2 Proxy >= 7.11.0, < 7.15.2.
Is there a fix for CVE-2026-34454?
Yes. github.com/oauth2-proxy/oauth2-proxy/v7 (Go): upgrade to 7.15.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-34454 attacked?
It is attacked with physical access, in a software library.
Am I affected by CVE-2026-34454?
Check whether you run github.com/oauth2-proxy/oauth2-proxy (Go), github.com/oauth2-proxy/oauth2-proxy/v7 (Go) or OAuth2 Proxy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/oauth2-proxy/oauth2-proxy/v7 (Go): upgrade to 7.15.2 or later
    go get github.com/oauth2-proxy/oauth2-proxy/v7@v7.15.2

Technical details

A regression in OAuth2 Proxy (v7.11.0 to v7.15.1) prevents the sign-in page handler from clearing existing session cookies. In environments where the sign-in page is used as a component of the logout flow, the browser may retain a valid session cookie even after the user believes they have logged out. This is classified as insufficient session expiration (CWE-613) and session fixation (CWE-384). An attacker with physical access to a shared workstation can resume the previous user's authenticated session. The issue is resolved in version 7.15.2 by ensuring the session cookie is cleared at the beginning of the sign-in page handler.

Affected products

  • OAuth2 Proxy Project OAuth2 Proxy >= 7.11.0, < 7.15.2

Identifiers

  • CVE-2026-34454
  • GHSA-f24x-5g9q-753f
  • GO-2026-5341

Timeline

  • 2026-04-14: disclosed
  • 2026-04-14: patched: Fixed in version 7.15.2
  • 2026-04-14: advisory

References

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