CVE-2026-3472 Details
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
A vulnerability exists in Mattermost versions 10.11.x prior to 10.11.18, 11.6.x prior to 11.6.3, and 11.5.x prior to 11.5.6. These versions fail to properly enforce markdown image rendering restrictions in AI bot tool result posts. This flaw enables an authenticated attacker to exfiltrate data to an attacker-controlled server by injecting markdown image syntax into tool result content, which is then rendered by the victim's client.
Users can upgrade to Mattermost versions 11.8.0 or 11.7.0 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 26, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://mattermost.com/security-updates | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-693 | Protection Mechanism Failure | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mattermost mattermost server | >= 10.11.0, < 10.11.19 >= 11.5.0, < 11.5.7 >= 11.6.0, < 11.6.4 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 29, 2026 | Initial Analysis | [email protected] |
| Jun 26, 2026 | CVE Modified | CISA-ADP |
| Jun 26, 2026 | New CVE Received | [email protected] |