🔐 CVE Alert

CVE-2026-4858

HIGH 8.0

Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.

CVSS Score
8.0
EPSS Score
0.0%
EPSS Percentile
0th

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to check integration URL for path traversal which allows an malicious authenticated user to call an arbitrary API via system admin Mattermost auth token using via path traversal in integration action URL.. Mattermost Advisory ID: MMSA-2026-00640

CWE CWE-22
Vendor mattermost
Product mattermost
Published May 21, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Affected Versions

Mattermost / Mattermost
11.6.0 ≤ 11.6.0 11.5.0 ≤ 11.5.3 11.4.0 ≤ 11.4.4 10.11.0 ≤ 10.11.14

References

NVD ↗ CVE.org ↗ EPSS Data ↗
mattermost.com: https://mattermost.com/security-updates

Credits

daw10