PT-2020-8442 · Mattermost · Mattermost Server

Published 2020-06-19 · Updated 2026-01-17 · CVE-2017-18896

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/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: The issue allows attackers to add DEBUG lines to the logs via a REST API version 3 logging endpoint.

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. As a temporary workaround, consider restricting access to the REST API version 3 logging endpoint until a patch is available.

Fix

Incorrect Permission

Weakness Enumeration

CWE-732

Related Identifiers

CVE-2017-18896

GHSA-63WG-QMRV-7Q66

GO-2026-4299

SUSE-SU-2026:0142-1

Affected Products

Mattermost Server

References · 45

• https://nvd.nist.gov/vuln/detail/CVE-2017-18896 · Security Note
• https://osv.dev/vulnerability/CVE-2017-18896 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-63wg-qmrv-7q66 · Vendor Advisory
• https://mattermost.com/security-updates · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4299 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2026:0142-1 · Vendor Advisory
• https://github.com/mattermost/mattermost · Note
• https://github.com/mattermost/mattermost/commit/d38328976e2c8bb0fab91e656042a0d8ac37bc76 · Note
• https://github.com/mattermost/mattermost/commit/722fb1947a2e7395ccf16adce9206736d803a9f3 · Note
• https://github.com/mattermost/mattermost/commit/3c34e2b2dcb0fde96a10e68d877aa7d0ab511669 · Note
• https://suse.com/security/cve/CVE-2026-22688 · Note
• https://suse.com/security/cve/CVE-2026-21859 · Note
• https://suse.com/support/update/announcement/2026/suse-su-20260142-1 · Note
• https://suse.com/security/cve/CVE-2025-68954 · Note
• https://suse.com/security/cve/CVE-2026-22703 · Note