All vulnerabilities
CVE-2026-104900

MISP Stored XSS via Unescaped Count Field Value in Remote Event Preview Index

MISP MISP
Open in ThreatlineRecord JSON
CVSS
5.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.36%Chance of exploitation activity in the next 30 days, higher than 28% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in2.5.48Fixed versionCVE List
Published2 Oct 2026Updated 2 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

MISP contains a stored cross-site scripting (XSS) vulnerability in the index table rendering of the remote event preview. The count field template escaped the associated link URL but rendered the field value without HTML encoding. An attacker with the ability to create or modify events on a linked (remote) MISP server could craft an event identifier containing HTML or JavaScript markup. When a user on the local MISP instance views the remote event preview index, the unescaped value is rendered directly in the browser, allowing arbitrary script execution in the victim's session.

Preconditions:

  • A linked/remote MISP server is configured and connected to the local instance.
  • The attacker has sufficient access on the linked server to create or modify an event with a crafted identifier.
  • A victim user on the local instance views the remote event preview index page.

Impact:

  • Execution of arbitrary JavaScript in the context of the MISP web application.
  • Potential session hijacking, data exfiltration, or unauthorized actions performed on behalf of the authenticated user.

Affected versions: <2.5.48.

Text from CVE List

Affected versions 1

  • MISPaffected: all versions before 2.5.48CVE List

References 1