What’s Vulnerable › Vulnerabilities
CVE-2026-103321: MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image
- Severity: high (CVSS 8.3 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-30 · updated 2026-09-30
- Weakness: CWE-20
Description
MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature. The event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script. Preconditions: - An authenticated MISP user with the ability to create or modify an event graph entry. - A second user (the victim) who views the event graph and triggers the preview popover. Impact: - Execution of arbitrary JavaScript in the victim's browser within the MISP application context. - Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser. - Potential for performing actions on behalf of the victim within the MISP application. Affected: MISP versions prior to the fix (commit applied after v2.5.48).
Affected products
- MISP: before 2.5.48 — fixed in 2.5.48
How to fix
Upgrade to a fixed version: MISP 2.5.48. Check the vendor advisory for mitigations.
References
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