CVE-2026-103662 MISP Reflected XSS in Taxonomy Tag Confirmation Forms
Reflected XSS in MISP allows attackers to execute scripts in admin browsers via crafted URLs, potentially leading to session theft or privileged actions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-103662?
CVE-2026-103662 is a medium-severity cross-site scripting vulnerability in MISP, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
MISP contains a reflected cross-site scripting (XSS) vulnerability in the legacy taxonomy tag management confirmation forms (add tag and disable tag).
The affected forms echoed a user-supplied tag name value from the request unescaped into the rendered HTML output. An attacker who can induce a site administrator to visit a crafted URL containing a malicious tag name parameter can execute arbitrary JavaScript in the administrator's browser session.
Preconditions:
- The target must be running a MISP instance with the legacy taxonomy tag confirmation views enabled.
- The victim must be an authenticated site administrator.
- The victim must navigate to the attacker-crafted URL (e.g., via a phishing link).
Security impact:
- Execution of arbitrary client-side script in the context of the administrator's browser.
- Potential theft of session tokens, CSRF tokens, or other sensitive data accessible from the page.
- Potential for performing privileged actions on behalf of the administrator within the MISP interface.
Affected versions: <2.5.48.
Weakness: CWE-79
Which versions are affected by CVE-2026-103662?
How do I fix CVE-2026-103662?
No fix has been published for CVE-2026-103662 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-2026-103662 being exploited?
There is no known exploitation of CVE-2026-103662 in the wild and no public exploit code.
Sources
Also known as GHSA-p9m5-xwgx-8j69.