- 3.0LowCVSS base score
- 0.29%Exploitation in 30 daysEPSS · top 78% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By Mattermost
- 8 days later
· 8 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| MattermostCNA (assigner) | 3.1 | Low3.0 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:N/A:N |
| NVDNVD · Analyzed | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.29% · top 78% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 3.0.
Affected products
- affected 10.4.0 – ≤ 10.4.2
- affected 10.5.0
- affected 9.11.0 – ≤ 9.11.9
- unaffected 10.6.0
- unaffected 10.4.3
- unaffected 10.5.1
- unaffected 9.11.10
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/mattermost/mattermost/server/v8GHSA-9h6j-4ffx-cm84 (opens in a new tab)
What to do
Solution: Update Mattermost to versions 10.6.0, 10.4.3, 10.5.1, 9.11.10 or higher.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-11357 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-9h6j-4ffx-cm84 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-31363)Record last updated .