# CVE-2026-41059

> Vulnerability · severity: **HIGH** (CVSS 8.2).

## Description

OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions 7.5.0 through 7.15.1 have a configuration-dependent authentication bypass. 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`; and 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. A fix has been implemented in version 7.15.2 to normalize request paths more conservatively before skip-auth matching so fragment content does not influence allowlist decisions. 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 include replacing broad rules with exact, anchored public paths and explicit HTTP methods; rejecting requests whose path contains `%23` or `#` at the ingress, load balancer, or WAF level; and/or avoiding placing sensitive application paths behind broad `skip_auth_routes` rules.

## Key facts

- **CVE ID:** CVE-2026-41059
- **Published:** 2026-04-22
- **CVSS severity:** HIGH
- **CVSS base score:** 8.2
- **CWE codes:** CWE-288

## Affected products

- `oauth2_proxy_project:oauth2_proxy`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41059

## Citation

> AI Analytics. CVE-2026-41059. Retrieved 2026-08-22 from https://api.ai-analytics.org/cve/CVE-2026-41059. Derived from NIST NVD. Licensed CC0.

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