{"id":"CVE-2026-6333","sourceIdentifier":"responsibledisclosure@mattermost.com","published":"2026-05-18T09:16:23.430","lastModified":"2026-10-14T20:10:00.190","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582"},{"lang":"es","value":"Mattermost versiones 11.5.x menor o igual que 11.5.1, 10.11.x menor o igual que 10.11.13 no validan el encabezado Host al construir URLs de respuesta para comandos de barra personalizados, lo que permite a un atacante autenticado redirigir las respuestas de los comandos de barra a un servidor controlado por el atacante a través de un encabezado Host falsificado. ID de Aviso de Mattermost: MMSA-2026-00582"}],"affected":[{"source":"responsibledisclosure@mattermost.com","affectedData":[{"vendor":"Mattermost","product":"Mattermost","defaultStatus":"unaffected","versions":[{"version":"11.5.0","lessThanOrEqual":"11.5.1","versionType":"semver","status":"affected"},{"version":"10.11.0","lessThanOrEqual":"10.11.13","versionType":"semver","status":"affected"},{"version":"11.6.0","status":"unaffected"},{"version":"11.5.2","status":"unaffected"},{"version":"10.11.14","status":"unaffected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"responsibledisclosure@mattermost.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N","baseScore":3.5,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":1.8,"impactScore":1.4},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","baseScore":5.0,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.1,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-05-18T14:36:12.538799Z","id":"CVE-2026-6333","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"responsibledisclosure@mattermost.com","type":"Secondary","description":[{"lang":"en","value":"CWE-918"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","versionStartIncluding":"10.11.0","versionEndExcluding":"10.11.14","matchCriteriaId":"413D9405-79C3-4299-B0DC-40D9EE5CC717"},{"vulnerable":true,"criteria":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","versionStartIncluding":"11.5.0","versionEndExcluding":"11.5.2","matchCriteriaId":"726AD6AD-6C01-45BB-9115-B8209717A6D4"}]}]}],"references":[{"url":"https://mattermost.com/security-updates","source":"responsibledisclosure@mattermost.com","tags":["Vendor Advisory"]}]}