CVE-2026-19867
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
59/100
Published: 2026-10-16
Modified: 2026-10-29
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Interaction
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
None
S:
Unchanged
C:
None
I:
None
A:
Low
Description
Mattermost versions 11.10.x <= 11.10.0, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10 fail to cap the number and size of mention keys stored in a user's notification properties, and to bound the quadratic multibyte-keyword matching performed for each post, which allows an authenticated user to degrade post-processing latency and consume excessive CPU on behalf of other members of any channel they share via storing an oversized notify_props.mention_keys list on their own profile.. Mattermost Advisory ID: MMSA-2026-00773
Weakness Classification (1)
Affected Software (2)
| Vendor | Product | Version |
|---|---|---|
| mattermost | mattermost_server | 11.7.0 – 11.7.11 |
| mattermost | mattermost_server | 11.10.0 |
References & Advisories (1)
Vendor Advisory