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CVE-2026-4858

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

Published: May 21, 2026Updated: May 21, 2026 Sources: CVE List NVD
NVD MITRE
8.0CVSS
HIGH

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

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

CVSS Vector Breakdown

AV:NAC:HPR:LUI:RS:CC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High

Weaknesses

CWE-22

Affected Products

Mattermost
Mattermost

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Collection
Discovery
View detailed technique mapping

References

https://mattermost.com/security-updates
mattermost.com

Timeline

Published
May 21, 2026
Last Updated
May 21, 2026

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