CVE-2026-96260

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-96260", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "state": "PUBLISHED", "assignerShortName": "Mattermost", "dateReserved": "2026-09-22T20:00:26.276Z", "datePublished": "2026-09-22T20:34:49.141Z", "dateUpdated": "2026-09-23T15:06:07.254Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "11.9.1", "status": "affected", "version": "11.9.0", "versionType": "semver"}, {"lessThanOrEqual": "11.8.5", "status": "affected", "version": "11.8.0", "versionType": "semver"}, {"lessThanOrEqual": "11.7.10", "status": "affected", "version": "11.7.0", "versionType": "semver"}, {"lessThanOrEqual": "11.10.1", "status": "affected", "version": "11.10.0", "versionType": "semver"}, {"version": "11.11.0", "status": "unaffected"}, {"version": "11.9.2", "status": "unaffected"}, {"version": "11.8.6", "status": "unaffected"}, {"version": "11.7.11", "status": "unaffected"}, {"version": "11.10.2", "status": "unaffected"}]}], "credits": [{"lang": "en", "type": "finder", "value": "alimursaliyev"}], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775"}], "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-789: Memory Allocation with Excessive Size Value", "cweId": "CWE-789"}]}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00775", "tags": ["vendor-advisory"]}], "solutions": [{"value": "Update Mattermost to versions 11.11.0, 11.9.2, 11.8.6, 11.7.11, 11.10.2 or higher.", "lang": "en"}], "source": {"advisory": "MMSA-2026-00775", "defect": ["https://mattermost.atlassian.net/browse/MM-70503"], "discovery": "EXTERNAL"}, "title": "Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user", "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-09-22T20:34:49.141Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-23T15:05:56.037132Z", "id": "CVE-2026-96260", "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": "2026-09-23T15:06:07.254Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-96260", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-09-23T15:05:56.037132Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-23T15:06:01.596Z"}}], "cna": {"title": "Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user", "source": {"defect": ["https://mattermost.atlassian.net/browse/MM-70503"], "advisory": "MMSA-2026-00775", "discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "finder", "value": "alimursaliyev"}], "metrics": [{"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"vendor": "Mattermost", "product": "Mattermost", "versions": [{"status": "affected", "version": "11.9.0", "versionType": "semver", "lessThanOrEqual": "11.9.1"}, {"status": "affected", "version": "11.8.0", "versionType": "semver", "lessThanOrEqual": "11.8.5"}, {"status": "affected", "version": "11.7.0", "versionType": "semver", "lessThanOrEqual": "11.7.10"}, {"status": "affected", "version": "11.10.0", "versionType": "semver", "lessThanOrEqual": "11.10.1"}, {"status": "unaffected", "version": "11.11.0"}, {"status": "unaffected", "version": "11.9.2"}, {"status": "unaffected", "version": "11.8.6"}, {"status": "unaffected", "version": "11.7.11"}, {"status": "unaffected", "version": "11.10.2"}], "defaultStatus": "unaffected"}], "solutions": [{"lang": "en", "value": "Update Mattermost to versions 11.11.0, 11.9.2, 11.8.6, 11.7.11, 11.10.2 or higher."}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00775", "tags": ["vendor-advisory"]}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775"}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-789", "description": "CWE-789: Memory Allocation with Excessive Size Value"}]}], "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-09-22T20:34:49.141Z"}}}, "cveMetadata": {"cveId": "CVE-2026-96260", "state": "PUBLISHED", "dateUpdated": "2026-09-23T15:06:07.254Z", "dateReserved": "2026-09-22T20:00:26.276Z", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "datePublished": "2026-09-22T20:34:49.141Z", "assignerShortName": "Mattermost"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "11.9.1", "status": "affected", "version": "11.9.0", "versionType": "semver"}, {"lessThanOrEqual": "11.8.5", "status": "affected", "version": "11.8.0", "versionType": "semver"}, {"lessThanOrEqual": "11.7.10", "status": "affected", "version": "11.7.0", "versionType": "semver"}, {"lessThanOrEqual": "11.10.1", "status": "affected", "version": "11.10.0", "versionType": "semver"}, {"status": "unaffected", "version": "11.11.0"}, {"status": "unaffected", "version": "11.9.2"}, {"status": "unaffected", "version": "11.8.6"}, {"status": "unaffected", "version": "11.7.11"}, {"status": "unaffected", "version": "11.10.2"}]}], "source": "responsibledisclosure@mattermost.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "C7DFF726-7FA7-48F9-90CE-3F6DAF6FA1C0", "versionEndExcluding": "11.7.11", "versionStartIncluding": "11.7.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "864932C7-FD92-48AC-8789-DF73D5CA9AAF", "versionEndExcluding": "11.8.6", "versionStartIncluding": "11.8.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "2F937268-2154-4B45-B9E0-8B3451070CD0", "versionEndExcluding": "11.9.2", "versionStartIncluding": "11.9.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "02B602D7-09A8-4AD1-A4A2-C70050E007AB", "versionEndExcluding": "11.10.2", "versionStartIncluding": "11.10.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775"}], "id": "CVE-2026-96260", "lastModified": "2026-10-07T16:37:42.773", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 3.6, "source": "responsibledisclosure@mattermost.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-96260", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-09-23T15:05:56.037132Z", "version": "2.0.3"}}]}, "published": "2026-09-22T21:17:35.027", "references": [{"source": "responsibledisclosure@mattermost.com", "tags": ["Vendor Advisory"], "url": "https://mattermost.com/security-updates"}], "sourceIdentifier": "responsibledisclosure@mattermost.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-789"}], "source": "responsibledisclosure@mattermost.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.9.0,11.9.1]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.8.0,11.8.5]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.7.0,11.7.10]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.10.0,11.10.1]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.11.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.9.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.8.6"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.7.11"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.10.2"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Mattermost", "source": "cna", "vendor": "Mattermost"}, "product": "mattermost", "vendor": "mattermost"}], "created": "2026-09-22T21:30:20.111535+00:00", "updated": "2026-09-22T22:00:08.068997+00:00", "vendors": ["mattermost", "mattermost$PRODUCT$mattermost"]}