PT-2020-8453 · Mattermost · Mattermost Server

Published 2020-06-19 · Updated 2026-03-03 · CVE-2017-18907

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions: Mattermost Server versions prior to 4.0.0 Mattermost Server version 3.10.2 Mattermost Server version 3.9.2

Description: An issue was discovered in Mattermost Server where XSS could occur via a channel header.

Recommendations: For Mattermost Server versions prior to 4.0.0, update to version 4.0.0 or later. For Mattermost Server version 3.10.2, update to version 4.0.0 or later. For Mattermost Server version 3.9.2, update to version 4.0.0 or later.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2017-18907

GHSA-42X9-RR3C-GR59

GO-2026-4459

SUSE-SU-2026:0757-1

Affected Products

Mattermost Server

References · 118

• https://osv.dev/vulnerability/SUSE-SU-2026:0757-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2017-18907 · Security Note
• https://osv.dev/vulnerability/CVE-2017-18907 · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4459 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-42x9-rr3c-gr59 · Vendor Advisory
• https://mattermost.com/security-updates · Vendor Advisory
• https://github.com/mattermost/mattermost · Note
• https://github.com/mattermost/mattermost/commit/312269ad0bd166174f07f9df7391fce714601600 · Note
• https://github.com/mattermost/mattermost/commit/a18479df0940be8503c9b88993490741793eba9e · Note
• https://github.com/mattermost/mattermost/commit/4519b03d95e8bfe1b2f74094673ae1a2f39f6b47 · Note
• https://suse.com/security/cve/CVE-2025-64111 · Note
• https://suse.com/security/cve/CVE-2026-0998 · Note
• https://suse.com/security/cve/CVE-2026-24122 · Note
• https://suse.com/security/cve/CVE-2026-22892 · Note
• https://t.me/cvenotify/4532 · Telegram Post