CVE-2026-3117 — Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0
CVE-2026-3117 — Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to properly check for permissions when processing commands in the Gitlab plugin which allows normal users to uninstall instances or setup webhook connections via the {{gitlab instance {option}}} or the {{/gitlab webhook
What This Means For You
- If your environment is affected by CWE-862, review your exposure and prioritize patching based on your environment. Monitor vendor advisories for CVE-2026-3117 updates and patches.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-3117 - Mattermost Gitlab Plugin Unauthorized Uninstall/Webhook Setup
title: CVE-2026-3117 - Mattermost Gitlab Plugin Unauthorized Uninstall/Webhook Setup
id: scw-2026-05-18-ai-1
status: experimental
level: high
description: |
Detects attempts to uninstall Mattermost Gitlab plugin instances or set up webhook connections via the API, which is possible for unprivileged users due to CVE-2026-3117 in affected versions. This rule specifically targets the API endpoints abused by the vulnerability.
author: SCW Feed Engine (AI-generated)
date: 2026-05-18
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-3117/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri|contains:
- '/plugins/gitlab/api/v1/uninstall'
- '/plugins/gitlab/api/v1/webhook'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-3117 | vulnerability | CVE-2026-3117 |
| CWE-862 | weakness | CWE-862 |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 18, 2026 at 12:16 UTC |
This content was curated and summarized by Shimi's Cyber World for informational purposes. It is not copied or republished in full. All intellectual property rights remain with the original author and source.
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