Guest accounts invited and added to channels by Welcomebot plugin
Priority LOW 17CWE-863Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
Mattermost WelcomeBot plugin fails to to validate the membership status when inviting or adding users to channels allowing guest accounts to be added or invited to channels by default.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00294 22nd percentileScored 2026-11-07
Fix Fixed Mattermost Plugins (Mattermost): 7.8.6, 7.10.3
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Mattermost | Mattermost Plugins | up to 7.8.5; up to 7.10.2 | 7.8.6, 7.10.3 | Patch available | CNA |
- Mattermost Plugins VendorMattermost Affected up to 7.8.5; up to 7.10.2 Fixed in 7.8.6, 7.10.3 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | before 7.8.6; 7.9.0 to before 7.10.3 | Vulnerable | Mattermost |
- cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions before 7.8.6; 7.9.0 to before 7.10.3 Vulnerable ·Mattermost
Remediation
- Fix · CNA Mattermost Plugins (Mattermost) Fixed in 7.8.6, 7.10.3
Timeline
- 2026-10-02 Threatist record created from CVE-2023-3613
- 2026-10-03 Alias added: GHSA-v326-937j-3p86
References
Advisory 1
More Mattermost Server vulnerabilities
- TI-2025-18933 Arbitrary file read in Mattermost Boards via import & export board archive CVSS 3.1CRITICAL 9.9
- TI-2025-04465 Path Traversal Leading to RCE by Any Authenticated Mattermost User CVSS 3.1CRITICAL 9.9
- TI-2017-14068 An issue was discovered in Mattermost Server before 3.6.2. CVSS 3.1CRITICAL 9.8
- TI-2017-14060 An issue was discovered in Mattermost Server before 3.8.2, 3.7.5, and 3.6.7. CVSS 3.1CRITICAL 9.8
- TI-2017-14048 An issue was discovered in Mattermost Server before 4.1.0, 4.0.4, and 3.10.3. CVSS 3.1CRITICAL 9.8
- TI-2025-14360 Arbitrary file read via block duplication in Mattermost Boards CVSS 3.1CRITICAL 9.9
Sources
- CVE-2023-3613 · CVE Program
- CVE-2023-3613 · NVD
- FIRST EPSS
- GHSA-v326-937j-3p86 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences