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Oauth2 ProxyApplication · Oauth2 Proxy Project

CVE-2026-34457

CRITICAL · 9.1 CVSS v3.1 Published 2026-04-14
Fix available
A fix is available. Upgrade to 7.15.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions prior to 7.15.2 contain a configuration-dependent authentication bypass in deployments where OAuth2 Proxy is used with an auth_request-style integration (such as nginx auth_request) and either --ping-user-agent is set or --gcp-healthchecks is enabled. In affected configurations, OAuth2 Proxy treats any request with the configured health check User-Agent value as a successful health check regardless of the requested path, allowing an unauthenticated remote attacker to bypass authentication and access protected upstream resources. Deployments that do not use auth_request-style subrequests or that do not enable --ping-user-agent/--gcp-healthchecks are not affected. This issue is fixed in 7.15.2.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OAuth2 Proxy versions before 7.15.2 have an authentication bypass when used with auth_request-style integrations (e.g., nginx auth_request) combined with --ping-user-agent or --gcp-healthchecks enabled. The proxy incorrectly treats any request with the configured health check User-Agent as a valid health check request, ignoring the requested path and allowing unauthenticated access to protected upstream resources.

MitigationUpgrade to OAuth2 Proxy 7.15.2. If immediate upgrade is not possible, verify that auth_request integration is not in use with --ping-user-agent or --gcp-healthchecks enabled, as disabling these flags removes the attack vector.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Oauth2 ProxyApplication
Affected:< 7.15.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check OAuth2 Proxy version
    Run 'oauth2-proxy --version' or 'oauth2-proxy -version' to obtain the installed version number
    Affected if Version is lower than 7.15.2
  2. Verify --ping-user-agent flag is enabled
    Inspect the OAuth2 Proxy command line arguments or configuration file for the presence of --ping-user-agent flag or 'ping_user_agent' setting
    Affected if --ping-user-agent is present and configured (the flag is enabled regardless of value)
  3. Verify --gcp-healthchecks flag is enabled
    Inspect the OAuth2 Proxy command line arguments or configuration file for the presence of --gcp-healthchecks flag or 'gcp_healthchecks' setting
    Affected if --gcp-healthchecks is present and configured (the flag is enabled regardless of value)
  4. Confirm nginx auth_request deployment pattern
    Check the deployment configuration to determine if OAuth2 Proxy is integrated with nginx using the auth_request directive
    Affected if OAuth2 Proxy is used behind nginx with auth_request and the version is < 7.15.2 with either health check flag enabled

You are affected if OAuth2 Proxy version is below 7.15.2 AND the deployment uses nginx auth_request integration AND either --ping-user-agent or --gcp-healthchecks flags are enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 7.15.2 or later
Fixed in 7.15.2
Interim mitigation

Upgrade to OAuth2 Proxy 7.15.2. If immediate upgrade is not possible, verify that auth_request integration is not in use with --ping-user-agent or --gcp-healthchecks enabled, as disabling these flags removes the attack vector.

Recommended fix High confidence

7.15.2

  1. 1. Identify current OAuth2 Proxy version by checking the binary or deployment configuration
  2. 2. Plan upgrade to version 7.15.2 or later, reviewing release notes for any changes
  3. 3. Test the upgrade in a staging or non-production environment first
  4. 4. After upgrade, verify that authentication is properly enforced for protected resources
  5. 5. If using auth_request integration with --ping-user-agent or --gcp-healthchecks, confirm health checks still function correctly after patching
Caveat Review release notes for version 7.15.2; no major breaking changes expected based on security patch nature

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Oauth2 Proxy Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-34457 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data