{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-2455","assignerOrgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","state":"PUBLISHED","assignerShortName":"Mattermost","dateReserved":"2026-02-13T10:45:36.473Z","datePublished":"2026-03-16T14:53:31.280Z","dateUpdated":"2026-03-16T18:38:07.619Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"11.3.0","status":"affected","version":"11.3.0","versionType":"semver"},{"lessThanOrEqual":"11.2.2","status":"affected","version":"11.2.0","versionType":"semver"},{"lessThanOrEqual":"10.11.10","status":"affected","version":"10.11.0","versionType":"semver"},{"version":"11.4.0","status":"unaffected"},{"version":"11.3.1","status":"unaffected"},{"version":"11.2.3","status":"unaffected"},{"version":"10.11.11","status":"unaffected"}]}],"credits":[{"lang":"en","type":"finder","value":"winfunc"}],"descriptions":[{"lang":"en","value":"Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to canonicalize IPv4-mapped IPv6 addresses before reserved IP validation which allows an attacker to perform SSRF attacks against internal services via IPv4-mapped IPv6 literals (e.g., [::ffff:127.0.0.1]).. Mattermost Advisory ID: MMSA-2026-00585"}],"metrics":[{"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE","version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","baseSeverity":"MEDIUM","baseScore":4.3},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-918: Server-Side Request Forgery (SSRF)","cweId":"CWE-918"}]}],"references":[{"url":"https://mattermost.com/security-updates","name":"MMSA-2026-00585","tags":["vendor-advisory"]}],"solutions":[{"value":"Update Mattermost to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher.","lang":"en"}],"source":{"advisory":"MMSA-2026-00585","defect":["https://mattermost.atlassian.net/browse/MM-67262"],"discovery":"EXTERNAL"},"title":"SSRF bypass via IPv4-mapped IPv6 literals","providerMetadata":{"orgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","shortName":"Mattermost","dateUpdated":"2026-03-16T14:53:31.280Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-16T18:37:36.914842Z","id":"CVE-2026-2455","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-16T18:38:07.619Z"}}]}}