CVE-2026-104906 MISP TAXII Object Viewer Stored XSS via Unescaped JSON Output
Attackers can inject malicious JavaScript into MISP via crafted TAXII objects, leading to session hijacking or data theft for authenticated users.
- 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-2026-104906?
CVE-2026-104906 is a medium-severity cross-site scripting vulnerability in MISP, published on 2 Oct 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 cross-site scripting (XSS) vulnerability in the TAXII object viewer. When displaying a remote TAXII object, the JSON content of string properties was rendered directly into an HTML pre block without HTML-encoding. An attacker who can control or influence the content of a TAXII object (e.g., by publishing a malicious object to a TAXII server that the victim's MISP instance subscribes to) can inject arbitrary HTML or JavaScript that executes in the context of the victim's MISP session.
Preconditions:
- The victim must be an authenticated MISP user with access to the TAXII object viewer.
- The victim must open or view the crafted TAXII object.
Impact:
- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.
- Potential theft of session tokens, API keys, or other sensitive data accessible from the MISP interface.
- Potential for performing actions on behalf of the authenticated user.
Affected versions: <2.5.48.
Weakness: CWE-79
Which versions are affected by CVE-2026-104906?
How do I fix CVE-2026-104906?
No fix has been published for CVE-2026-104906 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-2026-104906 being exploited?
There is no known exploitation of CVE-2026-104906 in the wild and no public exploit code.
Sources
Also known as GHSA-x6q8-3wfm-g2w6.