GHSA-9h6j-4ffx-cm84 · Severity: low · Ecosystem: go — Mattermost doesn't restrict domains LLM can request to contact upstream
Mattermost versions 10.4.x <= 10.4.2, 10.5.x <= 10.5.0, 9.11.x <= 9.11.9 fail to restrict domains the LLM can request to contact upstream which allows an authenticated user to exfiltrate data from an arbitrary server accessible to the victim via performing a prompt injection in the AI plugin's Jira tool.
Conclusion & alert: CVE-2025-31363 is rated Low Risk (16.5/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.23%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.28% | 0.23% | -0.05% |
| 2 | 2026-06-09 | 0.16% | 0.28% | +0.12% |
| 3 | 2026-02-10 | — | 0.16% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 3.0 | 3.1 | LOW |
|
1.3 | 1.4 | [email protected] |
| 6.5 | 3.1 | MEDIUM |
|
2.8 | 3.6 | [email protected] |
GHSA-9h6j-4ffx-cm84 · Severity: low · Ecosystem: go — Mattermost doesn't restrict domains LLM can request to contact upstream
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mattermost | mattermost_server | >= 9.11.0, < 9.11.10 | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
| mattermost | mattermost_server | >= 10.4.0, < 10.4.3 | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* |
| mattermost | mattermost_server | 10.5.0 | cpe:2.3:a:mattermost:mattermost_server:10.5.0:-:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://mattermost.com/security-updates | Vendor Advisory |