CVE-2026-86440

Source
https://cve.org/CVERecord?id=CVE-2026-86440
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86440.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-86440
Published
2026-09-07T12:35:10Z
Modified
2026-09-10T03:30:27Z
Severity
  • 5.1 (Medium) CVSS_V4 - 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 CVSS Calculator
Summary
MISP Dashboard Button Widget Allows Stored XSS via Unsafe javascript: and Backslash URLs
Details

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

Database specific
{
    "cna_assigner": "CIRCL",
    "cwe_ids": [
        "CWE-20",
        "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86440.json"
}
References

Affected packages

Git / github.com/misp/misp

Affected ranges

Type
GIT
Repo
https://github.com/misp/misp
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Database specific
Show details
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "2.5.45"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86440.json"