CVE-2026-2476
HIGHCVE-2026-2476 is a high-severity (CVSS 7.6) Information Exposure vulnerability in github.com/mattermost/mattermost-plugin-msteams. O3 Security confirms whether CVE-2026-2476 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
MS Teams plugin sensitive config values not properly masked in support packets
Blast Radius
github.com/mattermost/mattermost-plugin-msteamsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Mattermost Plugins versions <=2.0.3.0 fail to properly mask sensitive configuration values which allows an attacker with access to support packets to obtain original plugin settings via exported configuration data. Mattermost Advisory ID: MMSA-2026-00606
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-plugin-msteams | all versions | 1.15.1-0.20260102165339-036c761bd3cb |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/mattermost/mattermost-plugin-msteams. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/mattermost/mattermost-plugin-msteams to 1.15.1-0.20260102165339-036c761bd3cb or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-2476 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-2476 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-2476. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-2476 in your dependencies?
O3 detects CVE-2026-2476 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.