{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-5755","assignerOrgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","state":"PUBLISHED","assignerShortName":"Mattermost","dateReserved":"2026-04-07T16:22:49.762Z","datePublished":"2026-05-22T10:18:49.798Z","dateUpdated":"2026-05-22T12:15:24.414Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Mattermost","vendor":"Mattermost","versions":[{"lessThanOrEqual":"11.6.0","status":"affected","version":"11.6.0","versionType":"semver"},{"lessThanOrEqual":"11.5.2","status":"affected","version":"11.5.0","versionType":"semver"},{"lessThanOrEqual":"11.5.3","status":"affected","version":"11.5.0","versionType":"semver"},{"lessThanOrEqual":"11.4.4","status":"affected","version":"11.4.0","versionType":"semver"},{"lessThanOrEqual":"10.11.14","status":"affected","version":"10.11.0","versionType":"semver"},{"version":"11.7.0","status":"unaffected"},{"version":"11.6.1","status":"unaffected"},{"version":"11.5.3","status":"unaffected"},{"version":"11.5.4","status":"unaffected"},{"version":"11.4.5","status":"unaffected"},{"version":"10.11.15","status":"unaffected"}]}],"credits":[{"lang":"en","type":"finder","value":"ZephrFish"}],"descriptions":[{"lang":"en","value":"Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.2, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate the TIFF IFD offset in the image header before allocating memory, which allows authenticated users with file upload or posting permissions to cause a denial of service (server OOM) via uploading a crafted TIFF file or posting a URL that serves one.. Mattermost Advisory ID: MMSA-2026-00648"}],"metrics":[{"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseSeverity":"MEDIUM","baseScore":6.5},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","description":"CWE-400 Uncontrolled Resource Consumption","cweId":"CWE-400"}]}],"references":[{"url":"https://mattermost.com/security-updates","name":"MMSA-2026-00648","tags":["vendor-advisory"]}],"solutions":[{"value":"Update Mattermost to versions 11.7.0, 11.6.1, 11.5.3, 11.5.4, 11.4.5, 10.11.15 or higher.","lang":"en"}],"source":{"advisory":"MMSA-2026-00648","defect":["https://mattermost.atlassian.net/browse/MM-68224"],"discovery":"EXTERNAL"},"title":"Denial of service via crafted TIFF file upload","providerMetadata":{"orgId":"9302f53e-dde5-4bf3-b2f2-a83f91ac0eee","shortName":"Mattermost","dateUpdated":"2026-05-22T10:18:49.798Z"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-22T12:15:17.938601Z","id":"CVE-2026-5755","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":"2026-05-22T12:15:24.414Z"}}]}}