GHSA-76vf-mpmx-777j
HIGHGHSA-76vf-mpmx-777j is a high-severity (CVSS 8) Cross-site Scripting (XSS) vulnerability in org.graylog2:graylog2-server. O3 Security confirms whether GHSA-76vf-mpmx-777j is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Graylog Allows Session Takeover via Insufficient HTML Sanitization
Real-World Exposure
org.graylog2:graylog2-server☕org.graylog2:graylog2-serverReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Impact
It is possible to obtain user session cookies by submitting an HTML form as part of an Event Definition Remediation Step field. For this attack to succeed, the attacker needs a user account with permissions to create event definitions, while the user must have permissions to view alerts. Additionally, an active Input must be present on the Graylog server that is capable of receiving form data (e.g. a HTTP input, TCP raw or syslog etc).
Patches
Workarounds
None, as long as the relatively rare prerequisites are met.
Analysis provided by Fabian Yamaguchi - Whirly Labs (Pty) Ltd
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.graylog2:graylog2-server | all versions | 6.0.14 |
| ☕Maven | org.graylog2:graylog2-server | ≥ 6.1.0&&< 6.1.10 | 6.1.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.graylog2:graylog2-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 org.graylog2:graylog2-server to 6.0.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-76vf-mpmx-777j 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-76vf-mpmx-777j 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-76vf-mpmx-777j. 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-76vf-mpmx-777j in your dependencies?
O3 detects GHSA-76vf-mpmx-777j across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.