GHSA-M9P6-76X3-7VXP
Vulnerability from github – Published: 2026-09-07 15:33 – Updated: 2026-09-07 15:33Affected 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
{
"affected": [],
"aliases": [
"CVE-2026-86440"
],
"database_specific": {
"cwe_ids": [
"CWE-20"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-07T13:20:43Z",
"severity": "MODERATE"
},
"details": "Affected versions of MISP insufficiently validate URLs used by dashboard widgets, particularly the Button widget.\n\n\nThe widget\u0027s 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\u0027s URL parsing.\n\n\nAs a result, values such as javascript: URLs or backslash-based authority forms could reach the generated anchor\u0027s 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:\n\n\n\u201cjavascript: and backslash URLs reached the href (stored XSS)\u201d.\n\n\nThe 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.\n\nVersion affected: \u22642.5.45",
"id": "GHSA-m9p6-76x3-7vxp",
"modified": "2026-09-07T15:33:53Z",
"published": "2026-09-07T15:33:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86440"
},
{
"type": "WEB",
"url": "https://github.com/MISP/MISP/commit/adf704e94"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.