Umbraco.Forms has Path Traversal and File Enumeration Vulnerabilities in Linux/Mac

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.0 · 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 · score source

EPSS

• CVE-2026-24687: 0.46% estimated exploitation activity in the next 30 days; percentile 39.61 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact 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

Published by the source

30 Jan 2026, 14:43 UTC

Last modified by the source

30 Jan 2026, 14:43 UTC

Source last checked

26 Oct 2026, 17:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hm5p-82g6-m3xh

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-24687

Advisory: Umbraco.Forms has Path Traversal and File Enumeration Vulnerabilities in Linux/Mac
IDs: CVE-2026-24687, GHSA-hm5p-82g6-m3xh
Record: https://patchnext.com/advisories/cve-2026-24687 (revision 1, source checked 26 Oct 2026, 17:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: umbraco.forms 17.1.1, 16.4.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet umbraco.forms: affected >= 16.0.0, < 16.4.1; >= 17.0.0, < 17.1.1; fixed in 17.1.1, 16.4.1

## Suggested inspection (read-only)
- NuGet umbraco.forms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on umbraco.forms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hm5p-82g6-m3xh (GitHub-reviewed advisory GHSA-hm5p-82g6-m3xh lists affected ranges: NuGet umbraco.forms >=16.0.0 =17.0.0 <17.1.1)

Commands are suggestions: review each one before running it.