{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-40575 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-40575 is a critical authentication bypass vulnerability in oauth2-proxy, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-40575 and fix it if it is affected.\n\nWhat it is: CVE-2026-40575 is a critical authentication bypass vulnerability in oauth2-proxy, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-40575 in the wild and no public exploit code.\n\nAffected product: oauth2-proxy. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-40575/ (Markdown: https://insights.sbomify.com/CVE-2026-40575/index.md)","id":"CVE-2026-40575","markdown":"https://insights.sbomify.com/CVE-2026-40575/index.md","name":"CVE-2026-40575","record":{"aliases":["MINI-3f4m-gp5w-9f2p","MINI-mmxf-q5j4-jm29","RHSA-2026:58471"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"OAuth2 reverse proxy","requires_auth":"none","summary":"Attackers can bypass authentication and access protected routes by spoofing the X-Forwarded-Uri header in specific reverse proxy configurations.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"oauth2_proxy","vendor":"oauth2_proxy_project"}],"cvss":{"score":9.1,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-290","name":"Authentication Bypass by Spoofing"}],"description":"OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions 7.5.0 through 7.15.1 may trust a client-supplied `X-Forwarded-Uri` header when `--reverse-proxy` is enabled and `--skip-auth-regex` or `--skip-auth-route` is configured. An attacker can spoof this header so OAuth2 Proxy evaluates authentication and skip-auth rules against a different path than the one actually sent to the upstream application. This can result in an unauthenticated remote attacker bypassing authentication and accessing protected routes without a valid session. Impacted users are deployments that run oauth2-proxy with `--reverse-proxy` enabled and configure at least one `--skip-auth-regex` or `--skip-auth-route` rule. This issue is patched in `v7.15.2`. Some workarounds are available for those who cannot upgrade immediately. Strip any client-provided `X-Forwarded-Uri` header at the reverse proxy or load balancer level; explicitly overwrite `X-Forwarded-Uri` with the actual request URI before forwarding requests to OAuth2 Proxy; restrict direct client access to OAuth2 Proxy so it can only be reached through a trusted reverse proxy; and/or remove or narrow `--skip-auth-regex` / `--skip-auth-route` rules where possible. For nginx-based deployments, ensure `X-Forwarded-Uri` is set by nginx and not passed through from the client.","ecosystems":["Red Hat:hummingbird:1"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"OAuth2 Proxy has an Authentication Bypass via X-Forwarded-Uri Header Spoofing","id":"CVE-2026-40575","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"auth_bypass","year":"2026"},"n_packages":1,"n_references":1,"next":{"headline":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in excel-mcp-server","id":"CVE-2026-40576"},"packages":[{"ecosystem":"Red Hat:hummingbird:1","fixed":["0:7.15.4-0.1.hum1"],"introduced":["0"],"last_affected":[],"package":"oauth2-proxy","purl":"pkg:rpm/redhat/oauth2-proxy","source":"RHSA-2026:58471"}],"prev":{"headline":"OAuth2 Proxy has an Authorization Bypass in Email Domain Validation via Malformed Multi-@ Email Claims","id":"CVE-2026-40574"},"products":["oauth2-proxy"],"published":"2026-04-21","related":[{"cvss_score":9.1,"headline":"OAuth2 Proxy: Health Check User-Agent Matching Bypasses Authentication in auth_request Mode","id":"CVE-2026-34457","kev_date_added":null,"published":"2026-04-14"},{"cvss_score":9.1,"headline":"OAuth2-Proxy has authentication bypass in oauth2-proxy skip_auth_routes due to Query Parameter inclusion","id":"CVE-2025-54576","kev_date_added":null,"published":"2025-07-30"},{"cvss_score":8.8,"headline":"Cross-site Request Forgery (CSRF)","id":"CVE-2017-1000069","kev_date_added":null,"published":"2017-07-13"},{"cvss_score":8.2,"headline":"OAuth2 Proxy has an Authentication Bypass via Fragment Confusion in skip_auth_routes and skip_auth_regex","id":"CVE-2026-41059","kev_date_added":null,"published":"2026-04-21"},{"cvss_score":7.1,"headline":"Open Redirect in OAuth2 Proxy","id":"CVE-2020-11053","kev_date_added":null,"published":"2020-05-07"},{"cvss_score":6.8,"headline":"OAuth2 Proxy has an Authorization Bypass in Email Domain Validation via Malformed Multi-@ Email Claims","id":"CVE-2026-40574","kev_date_added":null,"published":"2026-04-21"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Red Hat","prefix":"RHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-07-15","vendors":["oauth2-proxy"]},"summary":"Attackers can bypass authentication and access protected routes by spoofing the X-Forwarded-Uri header in specific reverse proxy configurations.","url":"https://insights.sbomify.com/CVE-2026-40575/"}