CVE-2026-3472Markdown image rendering bypass in AI bot tool result posts in Mattermost
- 3.5LowCVSS base score
- 0.27%Exploitation in 30 daysEPSS · top 80% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Mattermost versions 10.11.x <= 10.11.18, 11.6.x <= 11.6.3, 11.5.x <= 11.5.6 fail to properly apply markdown image rendering restrictions to AI bot tool result posts, which allows an authenticated attacker to exfiltrate data to an attacker-controlled server via injecting markdown image syntax into tool result content rendered by a victim's client.. Mattermost Advisory ID: MMSA-2026-00619
Timeline
ID reserved
By Mattermost
- 4 months later
· 4 months 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 | Low3.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N |
| NVDNVD · Analyzed | 3.1 | Low3.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.27% · top 80% 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 3.5.
Affected products
- affected 10.11.0 – ≤ 10.11.18
- affected 11.6.0 – ≤ 11.6.3
- affected 11.5.0 – ≤ 11.5.6
- unaffected 11.7.0
- unaffected 10.11.19
- unaffected 11.6.4
- unaffected 11.5.7
What to do
Solution: Update Mattermost to versions 11.7.0, 10.11.19, 11.6.4, 11.5.7 or higher.
References
References1
- MMSA-2026-00619 (opens in a new tab)vendor-advisory
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-2026-39775 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (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-2026-3472)Record last updated .