CVE-2025-14822 — Inefficient Algorithmic Complexity in Mattermost Mattermost-server

CWE-407 — Inefficient Algorithmic ComplexityCWE-770 — Allocation of Resources Without Limits or Throttling6 documents5 sources
Severity
6.5MEDIUMNVD
CNA3.1
EPSS
0.0%
top 94.50%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
3
Github.com Mattermost Mattermost-serverMattermost ServerMattermost
Timeline
PublishedJan 16
Latest updateFeb 26

Description

Mattermost versions 10.11.x <= 10.11.8 fail to validate input size before processing hashtags which allows an authenticated attacker to exhaust CPU resources via a single HTTP request containing a post with thousands space-separated tokens

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitability: 2.8 | Impact: 3.6

Affected Packages3 packages

▶NVDmattermost/mattermost_server10.11.0 — 10.11.9
▶Gogithub.com/mattermost_mattermost-server10.11.0+incompatible — 10.11.9+incompatible+3
▶CVEListV5mattermost/mattermost10.11.0 — 10.11.8

🔴Vulnerability Details

4
OSV
Mattermost is vulnerable to CPU exhaustion via crafted HTTP request in github.com/mattermost/mattermost-server↗2026-02-26
▶
CVEList
DoS from quadratic complexity in model.ParseHashtags↗2026-01-16
▶
OSV
Mattermost is vulnerable to CPU exhaustion via crafted HTTP request↗2026-01-16
▶
GHSA
Mattermost is vulnerable to CPU exhaustion via crafted HTTP request↗2026-01-16
▶

🕵️Threat Intelligence

1
Wiz
CVE-2025-14822 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶
CVE-2025-14822 — Inefficient Algorithmic Complexity | cvebase