github.com/mattermost/mattermost-server Known Vulnerabilities & Fixes
github.com/mattermost/mattermost-server has 19 known security vulnerabilities in Go Modules. Upgrade to version 11.6.1 or later to resolve all known issues. Data sourced from OSV, enriched with EPSS exploit probability and CISA KEV.
Low Immediate Risk
No actively exploited vulnerabilities detected. Monitor and update in your next maintenance window.
Recommended safe version: 11.6.1
Upgrading to 11.6.1 or later resolves all 19 known vulnerabilities in github.com/mattermost/mattermost-server. Run: go get github.com/mattermost/mattermost-server@v11.6.1
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Security Summary
- 59 affected version ranges have been identified across these 19 advisories.
- 100% of known issues have a published fixed version.
- Remediation: go get -u github.com/mattermost/mattermost-server
Vulnerabilities
19 unique vulnerabilities — sorted by exploitation risk (KEV → EPSS → CVSS). Click a CVE/GHSA ID for full details. First disclosed May 24, 2022, most recently Jun 12, 2026 (1480 days apart).
| CVE / GHSA | Severity | Affected | Fixed In |
|---|---|---|---|
| CVE-2017-18908 Mattermost Server password reset email requests can be sent to attacker-provided email addresses | CRITICAL | All versions | 3.9.1-rc1, 3.10.1 |
| CVE-2017-18900 Mattermost Server is vulnerable CSV Injection | CRITICAL | All versions | 3.10.3, 4.0.3 |
| CVE-2025-4981 Mattermost allows authenticated users to write files to arbitrary locations | CRITICAL | All versions | 0.0.0-20250519205859-65aec10162f6 |
| CVE-2025-12421 Mattermost fails to to verify the token used during code exchange | CRITICAL | All versions | 11.0.3, 10.12.2, 10.11.5 (+1 more) |
| CVE-2025-12419 Mattermost fails to properly validate OAuth state tokens during OpenID Connect authentication | CRITICAL | All versions | 10.12.2, 10.11.5, 10.5.13 (+1 more) |
| CVE-2017-18915 Mattermost Server server restarts may provide attackers with API access | CRITICAL | All versions | 3.6.7-0.20170420152529-0968e4079e0a, 3.7.5, 3.8.2 |
| CVE-2017-18888 Mattermost Server is vulnerable to SQL Injection when executing multiple POST requests | CRITICAL | All versions | 4.1.2, 4.2.1, 4.3.0 |
| CVE-2017-18885 Mattermost Server allows attackers to gain privileges by accessing unintended API endpoints with users' credentials | CRITICAL | All versions | 4.1.2, 4.2.1, 4.3.0 |
| CVE-2025-58073 Mattermost has a Missing Authorization vulnerability | HIGH | All versions | 10.11.2, 10.10.3, 10.5.11 |
| CVE-2025-58075 Mattermost has a Missing Authorization vulnerability | HIGH | All versions | 10.11.2, 10.10.3, 10.5.11 |
| CVE-2026-6346 Mattermost doesn't sanitize sensitive configuration fields before including them in support packet generation | HIGH | All versions | 5.3.2-0.20260326202606-fac92f4a71f3 |
| CVE-2026-7387 Mattermost doesn't require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints | HIGH | 11.6.0 | 11.6.1, 11.5.5, 10.11.17 |
| CVE-2025-9079 Mattermost Path Traversal vulnerability | HIGH | All versions | 10.8.4, 10.5.9, 9.11.18 (+2 more) |
| CVE-2026-4858 Mattermost has a Path Traversal issue | HIGH | 11.6.0 | 11.6.1, 11.5.4, 11.4.5 (+1 more) |
| CVE-2026-6347 Mattermost doesn't sanitize sensitive configuration fields in the Mattermost Calls plugin | HIGH | All versions | 11.5.2, 10.11.14, 11.4.4 |
| CVE-2026-6961 Mattermost doesn't sanitize FileInfo.Name received from federated peers during shared channel file sync | HIGH | 11.6.0 | 11.6.1, 11.5.5, 10.11.17 |
| CVE-2026-24458 Mattermost fails to properly handle very long passwords | HIGH | All versions | 5.3.2-0.20260129164748-7201f42d955f, 10.11.11, 11.2.3 (+1 more) |
| CVE-2026-5740 Mattermost doesn't properly validate msgpack-encoded WebSocket frames before memory allocation | HIGH | 11.6.0 | 11.6.1, 11.5.4, 11.4.5 (+1 more) |
| CVE-2026-5308 Mattermost doesn't enforce request body size limits on plugin HTTP endpoints | HIGH | 11.6.0 | 11.6.1, 11.5.4, 11.4.5 (+1 more) |
About This Data
Vulnerability data for github.com/mattermost/mattermost-server is sourced from the Open Source Vulnerability (OSV) database, aggregating reports from GitHub Advisory Database, NIST NVD, and ecosystem-specific sources.
CVSS (Common Vulnerability Scoring System) scores reflect exploitability and impact. EPSS (Exploit Prediction Scoring System) scores indicate the probability of exploitation within the next 30 days. Vulnerabilities marked with are listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
Related Go Modules Packages
Other packages in this ecosystem, ranked by shared vulnerabilities where available.
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