SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-14298

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 limit decompressed content size and enforce the configured maximum file size in the Boards archive import handler, which allows an authenticated user…

MEDIUM 6.5EPSS 0.42%

Does this matter?

Lower severity and a low EPSS score (0.42%). Track it; it rarely justifies an emergency change on its own.

Description

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 limit decompressed content size and enforce the configured maximum file size in the Boards archive import handler, which allows an authenticated user to cause memory exhaustion or unbounded disk consumption via a crafted .boardarchive file uploaded to the import endpoint.. Mattermost Advisory ID: MMSA-2026-00713

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.42% probability · 36th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-409
Affected
mattermost/mattermost server
Source
responsibledisclosure@mattermost.com
EPSS trend
0%3%5%26 October 2026: 0.42%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.