CyberSecBulletin
CVE-2025-54576NVD status: Analyzed

oauth2-proxy: Authentication Bypass by Spoofing

Published Updated By the CyberSecBulletin desk

CVE-2025-54576 is a critical-severity authentication bypass by spoofing vulnerability in oauth2-proxy, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected oauth2-proxy versions: < 7.11.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.21% chance of exploitation within 30 days, higher than 69% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of oauth2-proxy you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Oauth2-proxyoauth2-proxy< 7.11.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
NoneAvailability is not affected.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (github.com).

Official description

OAuth2-Proxy is an open-source tool that can act as either a standalone reverse proxy or a middleware component integrated into existing reverse proxy or load balancer setups. In versions 7.10.0 and below, oauth2-proxy deployments are vulnerable when using the skip_auth_routes configuration option with regex patterns. Attackers can bypass authentication by crafting URLs with query parameters that satisfy configured regex patterns, allowing unauthorized access to protected resources. The issue stems from skip_auth_routes matching against the full request URI. Deployments using skip_auth_routes with regex patterns containing wildcards or broad matching patterns are most at risk. This issue is fixed in version 7.11.0. Workarounds include: auditing all skip_auth_routes configurations for overly permissive patterns, replacing wildcard patterns with exact path matches where possible, ensuring regex patterns are properly anchored (starting with ^ and ending with $), or implementing custom validation that strips query parameters before regex matching.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Authentication Bypass by Spoofing

This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

More Authentication Bypass by Spoofing vulnerabilities (CWE-290)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in oauth2-proxy

All oauth2-proxy vulnerabilities

Recent Authentication Bypass by Spoofing vulnerabilities

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