Vendor
Mattermost vulnerabilities
Updated . Rebuilt every hour.
Junglewise Threat Intelligence has tracked 103 vulnerabilities in Mattermost: 3 in the last 7 days and 38 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-96260, was published on 22 September 2026. 5 technologies have a page of their own.
- Last 7 days
- 3
- Last 90 days
- 38
- Critical, all time
- 0
- Exploited in the wild
- 0
About Mattermost
Open-source team collaboration and messaging platform with self-hosting capabilities.
Mattermost technologies
Latest Mattermost vulnerabilities
- CVE-2026-96260: Mattermost memory exhaustion in CSRF validation for plugin endpointsmediumCVSS 6.5EPSS 0.4%
- CVE-2026-96259: Mattermost internal-connection filter bypass in OAuth endpointsmediumCVSS 5.5EPSS 0.3%
- CVE-2026-95666: Mattermost denial of service via unbounded post ID arraymediumCVSS 4.3EPSS 0.4%
- CVE-2026-75588: Mattermost Desktop App URL scheme validation bypasslowCVSS 2.6EPSS 0.2%
- CVE-2026-12284: Mattermost Desktop App IPC validation bypass in leaveCall handlerlowCVSS 3.7EPSS 0.1%
- CVE-2026-75025: Mattermost Desktop App content restriction bypassmediumCVSS 4.7EPSS 0.2%
- CVE-2026-91181: Mattermost information disclosure in data retention teams endpointmediumCVSS 6.5EPSS 0.4%
- CVE-2026-12985: Mattermost OAuth redirect URI validation bypassmediumCVSS 6.8EPSS 0.3%
- CVE-2026-86349: Mattermost Markdown parser denial of servicemediumCVSS 4.3EPSS 0.4%
- CVE-2026-86348: Mattermost denial of service via handler panic in post-action requestmediumCVSS 4.3EPSS 0.4%
- CVE-2026-82920: Mattermost authorization bypass in access control policy endpointmediumCVSS 5.5EPSS 0.3%
- CVE-2026-9812: Mattermost Playbooks property field validation bypassmediumCVSS 6.5EPSS 0.4%
- CVE-2026-8821: Mattermost authorization bypass in playbook creationhighCVSS 7.1EPSS 0.3%
- CVE-2026-5132: Mattermost SDP message decompression denial of servicemediumCVSS 6.5EPSS 0.4%
- CVE-2026-14344: Mattermost permission bypass in board creationmediumCVSS 4.3EPSS 0.1%
- CVE-2026-14259: Mattermost board creation permissions bypass on archive importmediumCVSS 4.3EPSS 0.1%
- CVE-2026-13417: Mattermost Boards plugin denial of service via invalid field propertiesmediumCVSS 4.3EPSS 0.2%
- CVE-2026-12882: Mattermost ReDoS in Markdown autolink parsingmediumCVSS 4.3EPSS 0.2%
- CVE-2026-11993: Mattermost file upload goroutine exhaustion denial of servicemediumCVSS 4.3EPSS 0.2%
- CVE-2026-10556: Mattermost Microsoft Calendar plugin denial of service via webhook validation bypassmediumCVSS 5.3EPSS 0.3%
- CVE-2026-10542: Mattermost authorization bypass in channel action updatemediumCVSS 5EPSS 0.1%
- CVE-2026-9859: Mattermost privilege escalation in board channel reassignmentmediumCVSS 6.5EPSS 0.3%
- CVE-2026-9816: Mattermost privilege escalation via BoardMember.Scheme validation bypasshighCVSS 8.3EPSS 0.4%
- CVE-2026-7521: Mattermost path traversal in file deletion endpointmediumCVSS 5.5
- CVE-2026-10819: Mattermost denial of service via animated GIF emoji uploadsmediumCVSS 6.5
Most severe Mattermost vulnerabilities
Exploited in the wild first, then by severity and CVSS score.
- 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-2026-9816: Mattermost privilege escalation via BoardMember.Scheme validation bypasshighCVSS 8.3EPSS 0.4%
- CVE-2026-25773: Mattermost Focalboard SQL injection in category reorder APIhighCVSS 8.1EPSS 0.4%
- CVE-2026-4858: Mattermost path traversal in integration action URLhighCVSS 8EPSS 0.4%
- CVE-2026-6957: Mattermost Plugins path traversal in shared-channel attachment synchighCVSS 8
- CVE-2026-6961: Mattermost path traversal in shared channel file synchighCVSS 7.6EPSS 0.4%
- CVE-2026-6347: Mattermost Calls plugin information disclosure in support packetshighCVSS 7.6EPSS 0.4%
- CVE-2026-5740: Mattermost Server denial of service via msgpack WebSocket frameshighCVSS 7.5EPSS 0.6%
- CVE-2026-5308: Mattermost denial of service in plugin HTTP endpointshighCVSS 7.5EPSS 0.4%
Vulnerabilities per week
The last 13 weeks, by the week each vulnerability was published.
| Week of | Bar | Vulns | Critical |
|---|---|---|---|
| 6 Jul 2026 | 0 | 0 | |
| 13 Jul 2026 | 12 | 0 | |
| 20 Jul 2026 | 0 | 0 | |
| 27 Jul 2026 | 3 | 0 | |
| 3 Aug 2026 | 0 | 0 | |
| 10 Aug 2026 | 0 | 0 | |
| 17 Aug 2026 | 2 | 0 | |
| 24 Aug 2026 | 0 | 0 | |
| 31 Aug 2026 | 0 | 0 | |
| 7 Sep 2026 | 0 | 0 | |
| 14 Sep 2026 | 18 | 0 | |
| 21 Sep 2026 | 3 | 0 | |
| 28 Sep 2026 | 0 | 0 |
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/vendors/mattermost.json, 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, "Mattermost vulnerabilities", https://junglewise.ai/threats/vendors/mattermost, 28 September 2026.