CVE-2026-3495 — Unescaped variables during error page composition

CVE-2026-3495

Unescaped variables during error page composition PUBLISHED

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 11.5.0 through 11.5.1; affected 10.11.0 through 10.11.13; unaffected 11.6.0; unaffected 11.5.2; unaffected 10.11.14

CWE

CWE-79

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.