CVE-2026-3472Markdown image rendering bypass in AI bot tool result posts in Mattermost
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
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
- CVSS
- 3.5 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
- Weakness (CWE)
- CWE-693
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Mattermost
- NVD analysis
- Analyzed
- Record last updated
- Jun 26, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mattermost Mattermost mattermost:mattermost (from the name) | from 10.11.0 through 10.11.18; from 11.6.0 through 11.6.3; from 11.5.0 through 11.5.6; 11.7.0 not affected; 10.11.19 not affected; 11.6.4 not affected; 11.5.7 not affected | CNA record |
mattermost mattermost_server mattermost:mattermost_server | from 10.11.0 before 10.11.19; from 11.5.0 before 11.5.7; from 11.6.0 before 11.6.4 | NVD |
References
- https://mattermost.com/security-updatesvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.