CVE-2026-104901: MISP ID Translator: Unescaped Remote Event ID Enables Cross-Site Scripting via Linked Server
MISP contains a cross-site scripting (XSS) vulnerability in the ID Translator feature. When a user views the ID Translator page, the application queries linked (remote) MISP servers for corresponding event identifiers. The event ID returned by the remote server was rendered in the HTML output without proper output encoding.
A malicious or compromised linked server could return a crafted event ID containing arbitrary HTML or JavaScript markup. This markup would be rendered in the browser of any user in the host organization who views the ID Translator page, enabling session hijacking, credential theft, or other client-side attacks.
Preconditions:
- The victim must be an authenticated user of the host MISP instance.
- A linked server must be configured on the host instance.
- The victim must navigate to the ID Translator page for a given event.
Affected versions: <2.5.48.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MISPto a version that resolves this vulnerability.Fixed in 2.5.48
Event History
Frequently Asked Questions
Who is exposed to this issue?
Authenticated users of a MISP instance are exposed when the instance has a linked remote MISP server configured and they open the ID Translator page for an event. The linked server must be malicious or compromised to supply a crafted event ID.
Does exploitation require an attacker to have an account on the host MISP instance?
No. The attacker-controlled content is returned by a linked remote MISP server. However, exploitation requires an authenticated user on the host instance to navigate to the relevant ID Translator page.
Which versions are affected?
MISP versions earlier than 2.5.48 are affected.
What can be done if updating is not immediately possible?
Avoid using the ID Translator page on instances with linked remote MISP servers, especially where the linked servers are not fully trusted. Review configured linked servers and remove or disable connections to servers suspected of compromise.
How can an organization determine whether it may be affected?
Check whether the MISP version is earlier than 2.5.48 and whether linked remote MISP servers are configured. Systems meeting both conditions may expose authenticated users who use the ID Translator feature.