CVE-2026-27481

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From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an authorization bypass vulnerability allows unauthenticated or unauthorized users to view hidden (staff-only) tags and its associated data. All Discourse instances with tagging enabled and staff-only tag groups configured are impacted. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0."}, {"lang": "es", "value": "Discourse es una plataforma de discusi\u00f3n de c\u00f3digo abierto. Desde las versiones 2026.1.0-latest hasta antes de la 2026.1.3, 2026.2.0-latest hasta antes de la 2026.2.2, y 2026.3.0-latest hasta antes de la 2026.3.0, una vulnerabilidad de omisi\u00f3n de autorizaci\u00f3n permite a usuarios no autenticados o no autorizados ver etiquetas ocultas (solo para personal) y sus datos asociados. Todas las instancias de Discourse con etiquetado habilitado y grupos de etiquetas solo para personal configurados est\u00e1n afectadas. Este problema ha sido parcheado en las versiones 2026.1.3, 2026.2.2 y 2026.3.0."}], "id": "CVE-2026-27481", "lastModified": "2026-07-24T22:10:00.140", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-27481", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-07T14:18:28.633873Z", "version": "2.0.3"}}]}, "published": "2026-04-03T22:16:25.573", "references": [{"source": "security-advisories@github.com", "tags": ["Third Party Advisory"], "url": "https://github.com/discourse/discourse/security/advisories/GHSA-6c9x-3vrp-682x"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-200"}], "source": "security-advisories@github.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2026.1.0-latest,2026.1.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2026.2.0-latest,2026.2.2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2026.3.0-latest,2026.3.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "discourse", "source": "cna", "vendor": "discourse"}, "product": "discourse", "vendor": "discourse"}], "analysis": {"en": {"generated_at": "2026-04-22T19:51:48.973229+00:00", "value": {"mitigation_remediation": ["Upgrade Discourse to version 2026.1.3, 2026.2.2, or 2026.3.0, or any later patch release that contains the fix.", "Ensure that staff\u2011only tag groups remain properly configured in the platform\u2019s settings.", "If unable to upgrade immediately, isolate the vulnerable instances from public exposure until a patch is applied."], "summary": {"action": "Update Patch", "impact": "Unauthorized viewing of staff\u2011only tag data"}, "threat_synthesis": {"affected_systems": "Discourse instances that enable tagging and configure staff\u2011only tag groups are subject to this issue. It affects software versions 2026.1.0 through just before 2026.1.3, 2026.2.0 through just before 2026.2.2, and 2026.3.0 through just before 2026.3.0.", "description_and_impact": "The vulnerability stems from a flaw in Discourse\u2019s handling of tag routes. Users who lack authentication or proper authorization can request hidden tags meant to be visible only to staff, causing confidential tags and their linked data to be inadvertently exposed.", "risk_and_exploitability": "The CVSS score of 6.3 indicates medium severity. Because the vulnerability can be triggered by unauthenticated access, an attacker can expose confidential staff\u2011only tag data by simply requesting the hidden tag URL. The EPSS score of < 1% signifies a low probability of exploitation, and the vulnerability is not listed in the CISA KEV catalog. The attack path requires no special privileges beyond access to the public instance."}}}}, "created": "2026-04-06T21:22:26.670048+00:00", "updated": "2026-04-22T20:00:08.838913+00:00", "vendors": ["discourse", "discourse$PRODUCT$discourse"]}