The widget's URL is stored configuration controlled by a user. The previous renderer considered a URL safe if it appeared relative or if its parsed hostname matched the configured MISP hostname. That logic failed to reject dangerous schemes and URL forms that browsers normalize differently from PHP's URL parsing.
As a result, values such as javascript: URLs or backslash-based authority forms could reach the generated anchor's href and execute script or navigate to an attacker-controlled origin when another user interacted with the widget. The upstream commit describes the issue as:
“javascript: and backslash URLs reached the href (stored XSS)”.
The fix routes widget URLs through a shared DashboardURLValidator, rejects dangerous schemes, raw backslashes, control characters, and unauthorized absolute origins, and validates the URL both in the widget handler and renderer.
Version affected: ≤2.5.45
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
| Link | Providers |
|---|---|
| https://github.com/MISP/MISP/commit/adf704e94 |
|
Tue, 08 Sep 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 07 Sep 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Misp
Misp misp |
|
| Vendors & Products |
Misp
Misp misp |
Mon, 07 Sep 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Affected versions of MISP insufficiently validate URLs used by dashboard widgets, particularly the Button widget. The widget's URL is stored configuration controlled by a user. The previous renderer considered a URL safe if it appeared relative or if its parsed hostname matched the configured MISP hostname. That logic failed to reject dangerous schemes and URL forms that browsers normalize differently from PHP's URL parsing. As a result, values such as javascript: URLs or backslash-based authority forms could reach the generated anchor's href and execute script or navigate to an attacker-controlled origin when another user interacted with the widget. The upstream commit describes the issue as: “javascript: and backslash URLs reached the href (stored XSS)”. The fix routes widget URLs through a shared DashboardURLValidator, rejects dangerous schemes, raw backslashes, control characters, and unauthorized absolute origins, and validates the URL both in the widget handler and renderer. Version affected: ≤2.5.45 | |
| Title | MISP Dashboard Button Widget Allows Stored XSS via Unsafe javascript: and Backslash URLs | |
| Weaknesses | CWE-20 CWE-79 |
|
| References |
| |
| Metrics |
cvssV4_0
|
Projects
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Status: PUBLISHED
Assigner: CIRCL
Published:
Updated: 2026-09-08T14:51:34.403Z
Reserved: 2026-09-07T12:35:06.572Z
Link: CVE-2026-86440
Updated: 2026-09-08T14:51:30.612Z
Status : Undergoing Analysis
Published: 2026-09-07T13:20:43.153
Modified: 2026-09-08T15:18:55.433
Link: CVE-2026-86440
No data.
OpenCVE Enrichment
Updated: 2026-09-07T14:15:16Z