CVE-2026-41059

Released as part of v7.15.2

Workarounds

Users who cannot upgrade immediately can reduce exposure by tightening or removing skip_auth_routes and skip_auth_regex rules, especially patterns that use broad wildcards across path segments.

Recommended mitigations:

• Replace broad rules with exact, anchored public paths and explicit HTTP methods
• Reject requests whose path contains %23 or # at the ingress, load balancer, or WAF level
• Avoid placing sensitive application paths behind broad skip_auth_routes rules

A configuration-dependent authentication bypass exists in OAuth2 Proxy.

Deployments are affected when all of the following are true:

• Use of skip_auth_routes or the legacy skip_auth_regex * Use of patterns that can be widened by attacker-controlled suffixes, such as ^/foo/.*/bar$ causing potential exposure of /foo/secret * Protected upstream applications that interpret # as a fragment delimiter or otherwise route the request to the protected base path

In deployments that rely on these settings, an unauthenticated attacker can send a crafted request containing a number sign in the path, including the browser-safe encoded form %23, so that OAuth2 Proxy matches a public allowlist rule while the backend serves a protected resource.

Deployments that do not use these skip-auth options, or that only allow exact public paths with tightly scoped method and path rules, ARE NOT affected.

CVE-2026-41059 has a CVSS score of 8.2 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (7.15.2); upgrading removes the vulnerable code path.

Kodem intelligence

A fix has been implemented to normalize request paths more conservatively before skip-auth matching so fragment content does not influence allowlist decisions.

1. What is CVE-2026-41059? CVE-2026-41059 is a high-severity security vulnerability in github.com/oauth2-proxy/oauth2-proxy/v7 (go), affecting versions >= 7.5.0, < 7.15.2. It is fixed in 7.15.2.
2. How severe is CVE-2026-41059? CVE-2026-41059 has a CVSS score of 8.2 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/oauth2-proxy/oauth2-proxy/v7 are affected by CVE-2026-41059? github.com/oauth2-proxy/oauth2-proxy/v7 (go) versions >= 7.5.0, < 7.15.2 is affected.
4. Is there a fix for CVE-2026-41059? Yes. CVE-2026-41059 is fixed in 7.15.2. Upgrade to this version or later.
5. Is CVE-2026-41059 exploitable, and should I be worried? Whether CVE-2026-41059 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-41059 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-41059? Upgrade github.com/oauth2-proxy/oauth2-proxy/v7 to 7.15.2 or later.