CVE-2026-3472
Markdown image rendering bypass in AI bot tool result posts in Mattermost
CVSS Score
3.5
EPSS Score
0.0%
EPSS Percentile
0th
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
| CWE | CWE-693 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Jun 26, 2026 |
| Last Updated | Jun 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
Mattermost / Mattermost
10.11.0 ≤ 10.11.18 11.6.0 ≤ 11.6.3 11.5.0 ≤ 11.5.6
Credits
Juho Forsén