GHSA-Q9Q2-3PPX-MWQF

Graylog Allows Stored Cross-Site Scripting via Files Plugin and API Browser

Two minor vulnerabilities were identified in the Graylog2 enterprise server, which can be combined to carry out a stored cross-site scripting attack.
An attacker with the permission FILES_CREATE can exploit these vulnerabilities to upload arbitrary Javascript code to the Graylog2 server, which - upon requesting of the file by a user of the API browser - results in the execution of this Javascript code in the context of the Graylog frontend application.
This enables the attacker to carry out authenticated API requests with the permissions of the logged-in user, thereby taking over the user session.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

GHSA-Q9Q2-3PPX-MWQF has a CVSS score of 7.3 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (6.2.0); upgrading removes the vulnerable code path.

Kodem intelligence

The generic API has been removed in 6.2.0 rendering the attack vector unreachable and additional escaping has been added.

Analysis provided by Fabian Yamaguchi - Whirly Labs (Pty) Ltd

1. What is GHSA-Q9Q2-3PPX-MWQF? GHSA-Q9Q2-3PPX-MWQF is a high-severity cross-site scripting (XSS) vulnerability in org.graylog2:graylog2-server (maven), affecting versions < 6.2.0. It is fixed in 6.2.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. How severe is GHSA-Q9Q2-3PPX-MWQF? GHSA-Q9Q2-3PPX-MWQF has a CVSS score of 7.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of org.graylog2:graylog2-server are affected by GHSA-Q9Q2-3PPX-MWQF? org.graylog2:graylog2-server (maven) versions < 6.2.0 is affected.
4. Is there a fix for GHSA-Q9Q2-3PPX-MWQF? Yes. GHSA-Q9Q2-3PPX-MWQF is fixed in 6.2.0. Upgrade to this version or later.
5. Is GHSA-Q9Q2-3PPX-MWQF exploitable, and should I be worried? Whether GHSA-Q9Q2-3PPX-MWQF is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-Q9Q2-3PPX-MWQF is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-Q9Q2-3PPX-MWQF? Upgrade org.graylog2:graylog2-server to 6.2.0 or later.