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TI-2025-31091 Aliases CVE-2025-48953GHSA-fr6r-p8hv-x3c4

Umbraco Vulnerable to By-Pass of Configured Allowed Extensions for File Uploads

Priority LOW 28CWE-434Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-434.

Summary

Umbraco is an ASP.NET content management system (CMS). Starting in version 14.0.0 and prior to versions 15.4.2 and 16.0.0, it's possible to upload a file that doesn't adhere with the configured allowable file extensions via a manipulated API request. The issue is patched in versions 15.4.2 and 16.0.0. No known workarounds are available.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00193 9th percentileScored 2026-11-07
Fix Fixed Umbraco-CMS (umbraco): 15.4.2Umbraco.Cms (NuGet): 15.4.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
umbracoUmbraco-CMS14.0.0 to before 15.4.215.4.2Patch availableCNA
—Umbraco.Cms (NuGet)14.0.0 to before 15.4.215.4.2Patch availableGHSA-fr6r-p8hv-x3c4
  • Umbraco-CMS Vendorumbraco Affected 14.0.0 to before 15.4.2 Fixed in 15.4.2 Patch available CNA
  • Umbraco.Cms (NuGet) Vendor— Affected 14.0.0 to before 15.4.2 Fixed in 15.4.2 Patch available GHSA-fr6r-p8hv-x3c4

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:umbraco:umbraco_cms:*:*:*:*:*:*:*:*14.0.0 to before 15.4.2Vulnerableumbraco
  • cpe:2.3:a:umbraco:umbraco_cms:*:*:*:*:*:*:*:* Versions 14.0.0 to before 15.4.2 Vulnerable ·umbraco

Remediation

  • Fix · CNA Umbraco-CMS (umbraco) Fixed in 15.4.2
  • Fix · GHSA-fr6r-p8hv-x3c4 Umbraco.Cms (NuGet) Fixed in 15.4.2 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-48953
  2. 2026-10-03 Alias added: GHSA-fr6r-p8hv-x3c4

References

Patch 2

Advisory 1

Other 1

  • TI-2025-41183 An arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute… CVSS 3.1CRITICAL 10.0
  • TI-2012-05477 Umbraco CMS < 4.7.1 codeEditorSave.asmx RCE CVSS 4.0CRITICAL 9.3
  • TI-2021-22392 Umbraco v8.14.1 - 'baseUrl' SSRF CVSS 4.0MEDIUM 6.9
  • TI-2024-36846 A stored cross-site scripting (XSS) vulnerability in Umbraco CMS v14.3.1 allows attackers… CVSS 3.1MEDIUM 6.5
  • TI-2019-15240 Umbraco CMS 4.11.8 through 7.15.10, and 7.12.4, allows Remote Code Execution by… CVSS 3.1HIGH 7.2
  • TI-2020-04738 Cross-site scripting in Umbraco CMS CVSS 3.1MEDIUM 5.4
See all 56 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences