PT-2020-8438 · Mattermost · Mattermost Server

Published 2020-06-19 · Updated 2026-01-26 · CVE-2017-18892

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 4.2.0 Mattermost Server version 4.1.1 Mattermost Server version 4.0.5

Description: An issue was discovered in Mattermost Server where e-mail templates can have a field in which HTML content is not neutralized.

Recommendations: For versions prior to 4.2.0, update to version 4.2.0 or later. For version 4.1.1, update to version 4.2.0 or later. For version 4.0.5, update to version 4.2.0 or later.

Fix

Improper Encoding or Escaping of Output

Weakness Enumeration

CWE-116

Related Identifiers

CVE-2017-18892

GHSA-WJ5W-QGHH-GVQP

GO-2026-4317

SUSE-SU-2026:0292-1

Affected Products

Mattermost Server

References · 30

• https://nvd.nist.gov/vuln/detail/CVE-2017-18892 · Security Note
• https://osv.dev/vulnerability/GHSA-wj5w-qghh-gvqp · Vendor Advisory
• https://mattermost.com/security-updates · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2026:0292-1 · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4317 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2017-18892 · Vendor Advisory
• https://github.com/mattermost/mattermost · Note
• https://github.com/mattermost/mattermost/commit/d76946bdb545aba4088943fc523dabb459d22873 · Note
• https://github.com/mattermost/mattermost/commit/f5167f3ba645b829f4c28530e13be6c3db967255 · Note
• https://github.com/mattermost/mattermost/commit/4e05fbffed4d7ad75c0bb55d67d2c6f7cf9eaad6 · Note
• https://github.com/advisories/GHSA-wj5w-qghh-gvqp · Note
• https://suse.com/security/cve/CVE-2025-68383 · Note
• https://suse.com/security/cve/CVE-2026-22786 · Note
• https://suse.com/support/update/announcement/2026/suse-su-20260292-1 · Note
• https://suse.com/security/cve/CVE-2025-66292 · Note