CVE-2026-86348CWE-704

CVE-2026-86348

Medium · published September 14, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
29.4
In the wild
Unconfirmed
What it is

Mattermost versions <=11.9 11.0.9 11.4.8 11.7.7 10.22.11.0 fail to recover from handler panics, which allows an authenticated user to crash the plugin via a post-action request with an unexpected field type.. Mattermost Advisory ID: MMSA-2026-00701

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS v4.0
Not supplied
EPSS
0.00367 · 29.4th percentile
Weakness
CWE-704 · Incorrect Type Conversion or Cast
Published
2026-09-14T18:17Z
Affected products (4)
ProductVersionsFixed in
mattermost/mattermost_server≥ 10.11.0, < 10.11.2310.11.23
mattermost/mattermost_server≥ 11.7.0, < 11.7.811.7.8
mattermost/mattermost_server≥ 11.8.0, < 11.8.511.8.5
mattermost/mattermost_server≥ 11.9.0, < 11.9.111.9.1
References (1)
https://mattermost.com/security-updates · [email protected]
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 14 SEP 13:52Z
    MS Calendar plugin: unrecovered handler panics from malformed post-action requests could crash the plugin process
    cvelistv5