CVE-2026-3495

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to escape some variables that could contain malicious content during error page composition which allows an attacker with access to edit some site configuration to execute some malicious code via injecting some JS as part of those values.. Mattermost Advisory ID: MMSA-2026-00622

CVSS v3 3.8 LOW

3.8^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.2 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://mattermost.com/security-updates	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mattermost:mattermost_server::::::::
	cpe:2.3:a:mattermost:mattermost_server::::::::

History

19 May 2026, 17:37

Type	Values Removed	Values Added
First Time		Mattermost mattermost Server Mattermost
CPE		cpe:2.3:a:mattermost:mattermost_server::::::::
References	~~() https://mattermost.com/security-updates -~~	() https://mattermost.com/security-updates - Vendor Advisory

18 May 2026, 08:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-05-18 08:16

Updated : 2026-05-19 17:37

NVD link : CVE-2026-3495

Mitre link : CVE-2026-3495

CVE.ORG link : CVE-2026-3495

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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