{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-3114", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "state": "PUBLISHED", "assignerShortName": "Mattermost", "dateReserved": "2026-02-24T11:01:47.197Z", "datePublished": "2026-03-26T16:21:19.421Z", "dateUpdated": "2026-03-26T17:51:14.833Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Mattermost", "vendor": "Mattermost", "versions": [{"lessThanOrEqual": "11.4.0", "status": "affected", "version": "11.4.0", "versionType": "semver"}, {"lessThanOrEqual": "11.3.1", "status": "affected", "version": "11.3.0", "versionType": "semver"}, {"lessThanOrEqual": "11.2.3", "status": "affected", "version": "11.2.0", "versionType": "semver"}, {"lessThanOrEqual": "10.11.11", "status": "affected", "version": "10.11.0", "versionType": "semver"}, {"version": "11.5.0", "status": "unaffected"}, {"version": "11.4.1", "status": "unaffected"}, {"version": "11.3.2", "status": "unaffected"}, {"version": "11.2.4", "status": "unaffected"}, {"version": "10.11.12", "status": "unaffected"}]}], "credits": [{"lang": "en", "type": "finder", "value": "winfunc"}], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598"}], "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-409: Improper Handling of Highly Compressed Data (Data Amplification)", "cweId": "CWE-409"}]}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00598", "tags": ["vendor-advisory"]}], "solutions": [{"value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher.", "lang": "en"}], "source": {"advisory": "MMSA-2026-00598", "defect": ["https://mattermost.atlassian.net/browse/MM-67378"], "discovery": "EXTERNAL"}, "title": "Zip Bomb Denial of Service via Unrestricted Archive Decompression", "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-03-26T16:21:19.421Z"}, "x_generator": {"engine": "cvelib 1.8.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-3114", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-26T17:37:33.825174Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-26T17:51:14.833Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-3114", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-26T17:37:33.825174Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-26T17:47:26.384Z"}}], "cna": {"title": "Zip Bomb Denial of Service via Unrestricted Archive Decompression", "source": {"defect": ["https://mattermost.atlassian.net/browse/MM-67378"], "advisory": "MMSA-2026-00598", "discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "finder", "value": "winfunc"}], "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": "11.4.0", "versionType": "semver", "lessThanOrEqual": "11.4.0"}, {"status": "affected", "version": "11.3.0", "versionType": "semver", "lessThanOrEqual": "11.3.1"}, {"status": "affected", "version": "11.2.0", "versionType": "semver", "lessThanOrEqual": "11.2.3"}, {"status": "affected", "version": "10.11.0", "versionType": "semver", "lessThanOrEqual": "10.11.11"}, {"status": "unaffected", "version": "11.5.0"}, {"status": "unaffected", "version": "11.4.1"}, {"status": "unaffected", "version": "11.3.2"}, {"status": "unaffected", "version": "11.2.4"}, {"status": "unaffected", "version": "10.11.12"}], "defaultStatus": "unaffected"}], "solutions": [{"lang": "en", "value": "Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher."}], "references": [{"url": "https://mattermost.com/security-updates", "name": "MMSA-2026-00598", "tags": ["vendor-advisory"]}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598"}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-409", "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)"}]}], "providerMetadata": {"orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "shortName": "Mattermost", "dateUpdated": "2026-03-26T16:21:19.421Z"}}}, "cveMetadata": {"cveId": "CVE-2026-3114", "state": "PUBLISHED", "dateUpdated": "2026-03-26T17:51:14.833Z", "dateReserved": "2026-02-24T11:01:47.197Z", "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee", "datePublished": "2026-03-26T16:21:19.421Z", "assignerShortName": "Mattermost"}, "dataVersion": "5.2"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "D144BD1D-F65C-498D-BC8A-F3D718F47F4B", "versionEndExcluding": "10.11.12", "versionStartIncluding": "10.11.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "2E3E9B61-F003-45E4-9A04-8015A5CB8558", "versionEndExcluding": "11.2.4", "versionStartIncluding": "11.2.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "805ECFFC-82FD-4754-AF95-32167E1D41CB", "versionEndExcluding": "11.3.2", "versionStartIncluding": "11.3.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:mattermost:mattermost_server:11.4.0:*:*:*:*:*:*:*", "matchCriteriaId": "7B6A1FE2-D980-4755-A838-190A53A4D62B", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate decompressed archive entry sizes during file extraction which allows authenticated users with file upload permissions to cause a denial of service via crafted zip archives containing highly compressed entries (zip bombs) that exhaust server memory.. Mattermost Advisory ID: MMSA-2026-00598"}, {"lang": "es", "value": "Las versiones de Mattermost 11.4.x &lt;= 11.4.0, 11.3.x &lt;= 11.3.1, 11.2.x &lt;= 11.2.3, 10.11.x &lt;= 10.11.11 no validan los tama\u00f1os de las entradas de archivo descomprimidas durante la extracci\u00f3n de archivos, lo que permite a usuarios autenticados con permisos de carga de archivos causar una denegaci\u00f3n de servicio mediante archivos zip manipulados que contienen entradas altamente comprimidas (bombas zip) que agotan la memoria del servidor. ID de aviso de Mattermost: MMSA-2026-00598"}], "id": "CVE-2026-3114", "lastModified": "2026-03-30T19:40:45.843", "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"}]}, "published": "2026-03-26T17:16:42.480", "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-409"}], "source": "responsibledisclosure@mattermost.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.4.0,11.4.0]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.3.0,11.3.1]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.2.0,11.2.3]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[10.11.0,10.11.11]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.5.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.4.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.3.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.2.4"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "10.11.12"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Mattermost", "source": "cna", "vendor": "Mattermost"}, "product": "mattermost", "vendor": "mattermost"}], "analysis": {"en": {"generated_at": "2026-03-30T20:30:16.867004+00:00", "value": {"mitigation_remediation": ["Apply the Mattermost update to at least version 11.5.0 (or 10.11.12 for older releases) to fix the zip bomb denial of service vulnerability. If the update cannot be applied immediately, temporarily disable file upload capability or restrict it to essential users until the update is applied."], "summary": {"action": "Immediate Patch", "impact": "Denial of Service"}, "threat_synthesis": {"affected_systems": "The vulnerability affects Mattermost Server installations running the listed versions. Specifically, all deployments of versions 11.4.0 or earlier, 11.3.1 or earlier, 11.2.3 or earlier, and 10.11.11 or earlier are impacted, regardless of the environment or operating system.", "description_and_impact": "Mattermost versions 11.4.x (up to 11.4.0), 11.3.x (up to 11.3.1), 11.2.x (up to 11.2.3), and 10.11.x (up to 10.11.11) fail to validate the size of decompressed archive entries during extraction. An authenticated user with permission to upload files can craft a zip archive that expands to an enormous size (zip bomb). On extraction the server consumes large amounts of memory, eventually crashing or becoming unresponsive, thereby causing a denial of service. The weakness is a failure to enforce size limits on incoming files.", "risk_and_exploitability": "The CVSS score of 6.5 indicates moderate severity and the EPSS score of less than 1% suggests that exploitation is unlikely in the near term. The vulnerability is not listed in the CISA KEV catalog. An attacker needs only an authenticated account with file upload permissions to trigger the denial of service; no elevated privileges are required. Once activated, the server consumes excessive memory during zip extraction, potentially causing the Mattermost service to crash or become unresponsive for all users. While this does not expose data or modify system state, the availability impact can disrupt business operations relying on the messaging platform. Consequently, the risk is moderate but present, especially in environments where file uploads are enabled and the application is not promptly patched."}}}}, "created": "2026-03-27T08:33:56.776060+00:00", "updated": "2026-03-30T20:57:41.963706+00:00", "vendors": ["mattermost", "mattermost$PRODUCT$mattermost"]}