CVE-2026-103389 MISP Stored Cross-Site Scripting via Unvalidated Galaxy Icon Field in Correlation Graph
Attackers with galaxy editor permissions can inject scripts via unvalidated icon fields, leading to session hijacking or data manipulation in MISP.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-103389?
CVE-2026-103389 is a medium-severity cross-site scripting vulnerability in MISP, published on 30 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
MISP contains a stored cross-site scripting (XSS) vulnerability in the galaxy icon handling path. The icon field of a galaxy object was persisted without any server-side validation through the galaxy add, edit, and sync/import capture endpoints. The stored value was subsequently concatenated directly into HTML markup by the D3-based correlation graph rendering scripts (both the default and Overmind themes) using the .html() method.
A user holding the perm_galaxy_editor permission, which is granted to the stock User role, could store arbitrary HTML or JavaScript in the icon field. Any other user who opened the correlation graph of an event containing a cluster belonging to that galaxy would have the injected script executed in their browser session.
Impact:
- Arbitrary script execution in the context of the victim's MISP session
- Potential theft of session credentials, manipulation of displayed data, or initiation of actions on behalf of the victim
- Affects both the default and Overmind UI themes
Affected versions: <2.5.48
Which versions are affected by CVE-2026-103389?
How do I fix CVE-2026-103389?
No fix has been published for CVE-2026-103389 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-103389 being exploited?
There is no known exploitation of CVE-2026-103389 in the wild and no public exploit code.
Sources
Also known as GHSA-58w8-2929-fqhf.