CVE-2026-103321
MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image
- State
- Published
- Severity
- 8.3 High
- Published
- Sep 30, 2026
- Updated
- Sep 30, 2026
- Reserved
- Sep 30, 2026
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).
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.3 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N | CIRCL |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
MISPMISP |
|
References
- Security patchpatch
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