CVE-2026-34457
OAuth2 Proxy versions before 7.15.2 can let attackers bypass authentication when certain health‑check options are enabled. The flaw allows unauthenticated requests to reach protected upstream services. It is fixed in version 7.15.2.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
OAuth2 Proxy (oauth2_proxy_project) versions earlier than 7.15.2 that use auth_request‑style integration with --ping-user-agent or --gcp-healthchecks enabled.
Real-world impact
An attacker can send requests that appear as health checks and gain access to any resources protected by OAuth2 Proxy without authenticating.
Why this severity
The CVSS score of 9.1 reflects that the vulnerability is network‑based, requires no user interaction, and lets an attacker fully compromise confidentiality and integrity of protected data.
What to do about it
- 01Upgrade OAuth2 Proxy to version 7.15.2 or later.
- 02Restart the proxy service to apply the update.
NVD-referenced vendor advisory
Timeline
- Apr 14, 2026 · Apr 14, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 24, 2026 · 11d agoAdvisory updatedThe NVD record was last revised.
- Jul 26, 2026 · 10d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.
How it’s attacked
References & advisories
- github.com/oauth2-proxy/oauth2-proxy/r…release notes
- github.com/oauth2-proxy/oauth2-proxy/s…mitigationvendor advisory