CVE-2026-18256Medium· 4.3▾ SunlitMattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private t…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 23.7 · likelihood 0 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748
Mattermost >= 11.10.0 <= 11.10.0Mattermost >= 11.7.0 <= 11.7.9Mattermost >= 11.9.0 <= 11.9.1Mattermost >= 11.8.0 <= 11.8.5Update Mattermost to versions 11.11.0, 11.10.1, 11.7.10, 11.9.2, 11.8.6 or higher.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-18551Medium· 6.5Mattermost guest account privilege escalation via member roles API
CVE-2026-19076Medium· 4.4Mattermost fails to reject OAuth application sessions in account type switch, allowing account takeover via bearer token
CVE-2026-18223Medium· 5.0Mattermost invitation tokens not bound to invited email address allowing unauthorized team and private channel access
CVE-2026-19541Medium· 6.5Outgoing OAuth connection client secret exposure during connection validation
CVE-2026-19601Medium· 4.9Disclosure of AD/LDAP bind password via Test Connection
CVE-2026-19867Medium· 4.3Uncapped mention keys in user notification properties allow CPU exhaustion during post processing