CVE-2026-3524 | BDVDB-2026-324932 Detail

MattermostMattermost

Description#

Mattermost Plugin Legal Hold versions <=1.1.4 fail to halt request processing after a failed authorization check in ServeHTTP which allows an authenticated attacker to access, create, download, and delete legal hold data via crafted API requests to the plugin's endpoints. Mattermost Advisory ID: MMSA-2026-00621

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact high. Attack vector: network.

Weaknesses#

CWE-862 Missing Authorization

References#

https://mattermost.com/security-updates

Exploit#

No public exploit known

History#

Version 12026-04-06Record published in the CVE List.
Version 22026-04-07Most recent update recorded in the CVE List.

Published

Published: 2026-04-06
Last modified: 2026-04-07

Vendor information

Vendor: Mattermost
Product: Mattermost

All Mattermost vulnerabilities

Score

8.3 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 32.9.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Missing Authorization

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
<= 1.1.4
Fixed
Not stated
Vulnerable
Not stated
Fixed
1.1.5

Scoring System

CVSS v4.0

Not available

CVSS v3.1

8.3 High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	Low
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	High

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).