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github.com/mattermost/mattermost/server/v8 (Go) vulnerabilities
Updated . Rebuilt every hour.
Junglewise Threat Intelligence has tracked 207 vulnerabilities in github.com/mattermost/mattermost/server/v8 (Go): 0 in the last 7 days and 0 in the last 90 days, 2 of them critical and 0 exploited in the wild. The most recent, CVE-2026-3114, was published on 25 June 2026.
- Last 7 days
- 0
- Last 90 days
- 0
- Critical, all time
- 2
- Exploited in the wild
- 0
About github.com/mattermost/mattermost/server/v8 (Go)
Mattermost is an open-source team collaboration platform with messaging and integrations.
Latest github.com/mattermost/mattermost/server/v8 (Go) vulnerabilities
- CVE-2026-3114: Mattermost doesn't validate decompressed archive entry sizes during file extractionlowCVSS 3.1EPSS 0.4%
- CVE-2026-27659: GO-2026-5629 - Mattermost doesn't properly validate CSRF tokens in github.com/mattermost/mattermost-serverlowCVSS 3.1EPSS 0.2%
- CVE-2026-3115: Mattermost allows authenticated guest users to enumerate user IDs outside their allowed visibility scopelowCVSS 3.1EPSS 0.3%
- CVE-2026-28741: GO-2026-5495 - Mattermost doesn't validate CSRF tokens on an authentication endpoint in…lowCVSS 3.1EPSS 0.2%
- CVE-2026-27656: Mattermost allows attackers to take over arbitrary user accounts via overly permissive substring matching flawlowCVSS 3.1EPSS 0.3%
- CVE-2026-4274: GO-2026-5393 - Mattermost has an Incorrect Authorization issue in github.com/mattermost/mattermost-serverlowCVSS 3.1EPSS 0.2%
- CVE-2026-20719: Mattermost: Authenticated DoS through failure to prevent rendering of external SVGs on link embedslowCVSS 3.1EPSS 0.4%
- CVE-2026-3108: Mattermost allows attackers to manipulate administrator terminals via crafted messages containing ANSI and OSC escape…lowCVSS 3.1EPSS 0.3%
- CVE-2026-3112: Mattermost allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configurationlowCVSS 3.1EPSS 0.5%
- CVE-2026-8823: Mattermost incorrect authorization in demote-user APIlowCVSS 3.8EPSS 0.3%
- CVE-2026-7387: Mattermost privilege escalation in group syncable link and patch endpointshighCVSS 8.8EPSS 0.4%
- CVE-2026-7184: Mattermost sensitive information disclosure in Remote Cluster APImediumCVSS 6.5EPSS 0.4%
- CVE-2026-6961: Mattermost path traversal in shared channel file synchighCVSS 7.6EPSS 0.4%
- CVE-2026-6739: Mattermost privilege escalation in role patch APImediumCVSS 6.7EPSS 0.5%
- CVE-2026-6689: Mattermost missing authorization for invite settings during team creationmediumCVSS 4.3EPSS 0.3%
- CVE-2026-6046: Mattermost message interception via predictable bot usernamesmediumCVSS 5.3EPSS 0.3%
- CVE-2026-3433: Mattermost information disclosure in role_updated WebSocket eventsmediumCVSS 4.3EPSS 0.3%
- CVE-2026-4915: Mattermost Server denial of service via null webhook attachmentmediumCVSS 6.5EPSS 0.4%
- CVE-2026-5740: Mattermost Server denial of service via msgpack WebSocket frameshighCVSS 7.5EPSS 0.6%
- CVE-2026-4055: Mattermost incorrect authorization in Playbook run creationmediumCVSS 4.3EPSS 0.3%
- CVE-2026-6346: Mattermost sensitive information disclosure in support packet generationhighCVSS 8.7EPSS 0.4%
- CVE-2026-6345: Mattermost password disclosure in user creationmediumCVSS 6.5EPSS 0.4%
- CVE-2026-6343: Mattermost Incorrect Authorization in Playbooks via /get endpointmediumCVSS 4.3EPSS 0.3%
- CVE-2026-6339: Mattermost origin validation error in burn-on-read reveal endpointmediumCVSS 4.3EPSS 0.2%
- CVE-2026-6333: Mattermost Server SSRF via Host header in slash commandslowCVSS 3.5EPSS 0.2%
Most severe github.com/mattermost/mattermost/server/v8 (Go) vulnerabilities
Exploited in the wild first, then by severity and CVSS score.
- CVE-2025-12421: GO-2025-4170 - Mattermost fails to to verify the token used during code exchange in github.com/mattermost/mattermost-servercriticalCVSS 9.9EPSS 0.4%
- CVE-2025-12419: Mattermost fails to properly validate OAuth state tokens during OpenID Connect authenticationcriticalCVSS 9.9EPSS 0.4%
- CVE-2026-7387: Mattermost privilege escalation in group syncable link and patch endpointshighCVSS 8.8EPSS 0.4%
- CVE-2026-6346: Mattermost sensitive information disclosure in support packet generationhighCVSS 8.7EPSS 0.4%
- CVE-2026-6961: Mattermost path traversal in shared channel file synchighCVSS 7.6EPSS 0.4%
- CVE-2026-5740: Mattermost Server denial of service via msgpack WebSocket frameshighCVSS 7.5EPSS 0.6%
- CVE-2025-14273: Mattermost with Jira plugin enabled has Incorrect Implementation of Authentication AlgorithmhighCVSS 7.2EPSS 0.3%
- CVE-2026-6739: Mattermost privilege escalation in role patch APImediumCVSS 6.7EPSS 0.5%
- CVE-2026-7184: Mattermost sensitive information disclosure in Remote Cluster APImediumCVSS 6.5EPSS 0.4%
- CVE-2026-6345: Mattermost password disclosure in user creationmediumCVSS 6.5EPSS 0.4%
Vulnerabilities per week
Nothing was published in the last eight weeks. The last 13 weeks, by the week each vulnerability was published.
| Week of | Bar | Vulns | Critical |
|---|---|---|---|
| 17 Aug 2026 | 0 | 0 | |
| 24 Aug 2026 | 0 | 0 | |
| 31 Aug 2026 | 0 | 0 | |
| 7 Sep 2026 | 0 | 0 | |
| 14 Sep 2026 | 0 | 0 | |
| 21 Sep 2026 | 0 | 0 | |
| 28 Sep 2026 | 0 | 0 | |
| 5 Oct 2026 | 0 | 0 | |
| 12 Oct 2026 | 0 | 0 | |
| 19 Oct 2026 | 0 | 0 | |
| 26 Oct 2026 | 0 | 0 | |
| 2 Nov 2026 | 0 | 0 | |
| 9 Nov 2026 | 0 | 0 |
Embed a badge
A live badge for a README, a status page or an internal wiki: how many github.com/mattermost/mattermost/server/v8 (Go) vulnerabilities were published in the last 7 days and how many of them are critical, refreshed hourly.
[](https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8)<a href="https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8"><img src="https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8/badge.svg" alt="github.com/mattermost/mattermost/server/v8 (Go) vulnerabilities" /></a>How this is built
Junglewise Threat Intelligence collects vulnerabilities from NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories, and matches each one to the technologies and vendors it affects. Dates are the date a vulnerability was published, in UTC.
The pages are rebuilt from the database every hour. Frozen weekly and monthly reports never change once published, so they can be cited.
Use this data
The same data is at https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8.json, and this page as text at https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8.md, for scripts and language models. It is free to reuse under CC BY 4.0 with a link back to this page.
Cite as: Junglewise Threat Intelligence, "github.com/mattermost/mattermost/server/v8 (Go) vulnerabilities", https://junglewise.ai/threats/technologies/github-com-mattermost-mattermost-server-v8, 13 November 2026.