{"id":"CVE-2026-13417","title":"Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creation which allows an authenticated user with editor access to a board to crash th…","summary":"Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creation which allows an authenticated user with editor access to a board to crash th…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-754"],"vendor":"mattermost","product":"mattermost_server","affected":["mattermost_server >= 10.11.0, < 10.11.23","mattermost_server >= 11.7.0, < 11.7.8","mattermost_server >= 11.8.0, < 11.8.5","mattermost_server >= 11.9.0, < 11.9.1"],"patched":["mattermost_server 11.9.1"],"published":"2026-09-14","updated":"2026-10-07","sourceUpdated":"2026-10-07T16:17:21.987","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-13417","references":[{"url":"https://mattermost.com/security-updates","label":"responsibledisclosure@mattermost.com"}],"tags":["nvd","cve.org"],"epss":0.00367,"epssPercentile":0.30399,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-14T11:03:53.719633Z"},"ingestedAt":"2026-09-14T15:23:07.462Z","slug":"CVE-2026-13417","body":"## Overview\n\nMattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate the type of `fields.properties` on block creation which allows an authenticated user with editor access to a board to crash the Boards plugin worker and trigger a denial of service via a child block whose `fields.properties` is a non-object value. Mattermost Advisory ID: MMSA-2026-00710\n\n## Affected\n\n- `mattermost_server >= 10.11.0, < 10.11.23`\n- `mattermost_server >= 11.7.0, < 11.7.8`\n- `mattermost_server >= 11.8.0, < 11.8.5`\n- `mattermost_server >= 11.9.0, < 11.9.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `mattermost_server 11.9.1`","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}