Mattermost versions 11.7.x <= 11.7.10 fail to validate reserved system post types on the scheduled post creation and
Source GCVE Database
Not known to be exploited · CVSS 3.5 Low.
Data as of 26 Oct 2026, 16:36 UTC
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MattermostMattermost | Affected
| Fixed in– |
Description
Mattermost versions 11.7.x up to 11.7.10 contain a vulnerability where reserved system post types are not properly validated during scheduled post creation and publication. This flaw allows an authenticated channel member to publish messages that appear as trusted system events via the scheduled post endpoint. The vulnerability has a low severity rating and does not impact confidentiality or availability.