Answer in brief
CVE-2026-3472 records a Low severity (CVSS 3.5) vulnerability in Markdown image rendering bypass in AI bot tool result posts in Mattermost. The current sources do not mark it as known exploited. The current feed maps Mattermost/Mattermost (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Mattermost/Mattermost (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Mattermost/Mattermostgeneric | 10.11.0 || 11.6.0 || 11.5.0 | Not reported |
Published upstream
Jun 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 26, 2026
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
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-3472 records a Low severity (CVSS 3.5) vulnerability in Markdown image rendering bypass in AI bot tool result posts in Mattermost. The current sources do not mark it as known exploited. The current feed maps Mattermost/Mattermost (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Mattermost/Mattermost (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Mattermost/Mattermostgeneric | 10.11.0 || 11.6.0 || 11.5.0 | Not reported |
Published upstream
Jun 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 26, 2026
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
Quoted source text, attributed separately from HOL analysis.