GHSA-247x-7qw8-fp98
MEDIUMGHSA-247x-7qw8-fp98 is a medium-severity (CVSS 4.3) Uncontrolled Resource Consumption vulnerability in github.com/mattermost/mattermost-server. O3 Security confirms whether GHSA-247x-7qw8-fp98 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Mattermost doesn't rate limit login requests, allowing DoS
Real-World Exposure
github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-server🐹github.com/mattermost/mattermost-serverReal-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 versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to rate limit login requests which allows unauthenticated remote attackers to cause denial of service (server crash and restart) via HTTP/2 single packet attack with 100+ parallel login requests.. Mattermost Advisory ID: MMSA-2025-00566
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 11.4.0-rc1&&< 11.4.1 | 11.4.1 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 11.3.0-rc1&&< 11.3.2 | 11.3.2 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 11.2.0-rc1&&< 11.2.4 | 11.2.4 |
| 🐹Go | github.com/mattermost/mattermost-server | ≥ 10.11.0-rc1&&< 10.11.12 | 10.11.12 |
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-server. 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-server to 11.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-247x-7qw8-fp98 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 GHSA-247x-7qw8-fp98 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 GHSA-247x-7qw8-fp98. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-247x-7qw8-fp98 in your dependencies?
O3 detects GHSA-247x-7qw8-fp98 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.