CVE-2026-86351

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Source

https://cve.org/CVERecord?id=CVE-2026-86351

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86351.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-86351

Published

2026-09-07T09:59:34Z

Modified

2026-09-10T03:31:05Z

Severity

5.1 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N CVSS Calculator

Summary

MISP User Homepage Validation Allows Authenticated Open Redirect via Protocol-Relative URL

Details

Affected versions of MISP validate the user-configurable homepage by checking only whether the supplied path begins with /. That check is insufficient because protocol-relative URLs such as //attacker.example also begin with / but resolve to an external origin in browsers.

The vulnerable homepage value can be stored as a user setting and later used by the post-login routing logic. The commit explicitly identifies //attacker.example as a payload that passed validation and was emitted to the Location header after login.

The fix introduces a shared InternalRedirectValidator that rejects URLs containing a host, scheme, userinfo, unsafe leading // or /, malformed URLs, and control characters. It also revalidates homepage settings on read so legacy or internally written unsafe values cannot bypass the new storage-time validation.

Version affected: ≤2.5.45

Database specific

{
    "cna_assigner": "CIRCL",
    "cwe_ids": [
        "CWE-20",
        "CWE-601"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86351.json"
}

References

Affected packages

Git / github.com/misp/misp

Affected ranges

Type

GIT

Repo

https://github.com/misp/misp

Events

Introduced

Fixed

bd454f65a

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-2026-86351.json"