GHSA-HM5P-82G6-M3XH
Vulnerability from github – Published: 2026-01-30 14:43 – Updated: 2026-01-30 14:43Impact
It's possible for an authenticated backoffice-user to enumerate and traverse paths/files on the systems filesystem and read their contents, on Mac/Linux Umbraco installations using Forms. As Umbraco Cloud runs in a Windows environment, Cloud users aren't affected.
Patches
This issue affects versions 16 and 17 of Umbraco Forms and is patched in 16.4.1 and 17.1.1
Workarounds
If upgrading is not immediately possible, users can mitigate this vulnerability by:
* Configuring a WAF or reverse proxy to block requests containing path traversal sequences (../, ..\) in the fileName parameter of the export endpoint
* Restricting network access to the Umbraco backoffice to trusted IP ranges
* Blocking the /umbraco/forms/api/v1/export endpoint entirely if the export feature is not required
However, upgrading to the patched version is strongly recommended.
References
Credit to Kevin Joensen from Baldur Security for finding this vulnerability
{
"affected": [
{
"package": {
"ecosystem": "NuGet",
"name": "Umbraco.Forms"
},
"ranges": [
{
"events": [
{
"introduced": "16.0.0"
},
{
"fixed": "16.4.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "NuGet",
"name": "Umbraco.Forms"
},
"ranges": [
{
"events": [
{
"introduced": "17.0.0"
},
{
"fixed": "17.1.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-24687"
],
"database_specific": {
"cwe_ids": [
"CWE-22"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-30T14:43:18Z",
"nvd_published_at": "2026-01-29T20:16:10Z",
"severity": "MODERATE"
},
"details": "### Impact\nIt\u0027s possible for an authenticated backoffice-user to enumerate and traverse paths/files on the systems filesystem and read their contents, on Mac/Linux Umbraco installations using Forms. As Umbraco Cloud runs in a Windows environment, Cloud users aren\u0027t affected. \n\n### Patches\nThis issue affects versions 16 and 17 of Umbraco Forms and is patched in 16.4.1 and 17.1.1\n\n### Workarounds\nIf upgrading is not immediately possible, users can mitigate this vulnerability by:\n* Configuring a WAF or reverse proxy to block requests containing path traversal sequences (`../`, `..\\`) in the `fileName` parameter of the export endpoint\n* Restricting network access to the Umbraco backoffice to trusted IP ranges\n* Blocking the `/umbraco/forms/api/v1/export` endpoint entirely if the export feature is not required\n\nHowever, upgrading to the patched version is strongly recommended.\n\n### References\nCredit to Kevin Joensen from Baldur Security for finding this vulnerability",
"id": "GHSA-hm5p-82g6-m3xh",
"modified": "2026-01-30T14:43:18Z",
"published": "2026-01-30T14:43:18Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/umbraco/Umbraco.Forms.Issues/security/advisories/GHSA-hm5p-82g6-m3xh"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-24687"
},
{
"type": "PACKAGE",
"url": "https://github.com/umbraco/Umbraco.Forms.Issues"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Umbraco.Forms has Path Traversal and File Enumeration Vulnerabilities in Linux/Mac"
}
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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.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- 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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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