{"apiVersion":"1.0","identifier":"CVE-2026-9859","description":"Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21, 11.8.x <= 11.8.3 fail to enforce PermissionManageBoardRoles on the channelId field of the batch endpoint, which allows an authenticated board editor to relink any board they can edit to an arbitrary channel via a crafted PATCH request. Mattermost Advisory ID: MMSA-2026-00686","publishedAt":"2026-08-17T22:17:27","lastModifiedAt":"2026-08-19T13:28:57","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-9859","cvssScore":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","epssProbability":0.00253,"riskScore":0.66,"affectedProduct":"Mattermost","affectedVersions":"<=11.7.6, <=10.11.21, <=11.8.3","vulnerabilityType":"Web app","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-9859","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-9859","en":"https://www.redsauce.net/en/cves/CVE-2026-9859","fr":"https://www.redsauce.net/fr/cves/CVE-2026-9859","pt":"https://www.redsauce.net/pt/cves/CVE-2026-9859","de":"https://www.redsauce.net/de/cves/CVE-2026-9859","sk":"https://www.redsauce.net/sk/cves/CVE-2026-9859","el":"https://www.redsauce.net/el/cves/CVE-2026-9859"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-9859"}}