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CRITICAL severity

CVE-2025-67288 — Umbraco.Cms

CRITICALFix: github/advisory-database#6633

CVE-2025-67288 is a critical-severity (CVSS 10) Unrestricted File Upload vulnerability in Umbraco.Cms. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

Umbraco CMS has an arbitrary file upload vulnerability

Also known asGHSA-54mj-vcvj-q3v5
Published
Updated
Affected
1 pkg
Patched
See advisory
Exploits
None indexed
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-67288.

EPSS Exploitation Probability

via FIRST.org ↗
0.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs46th percentile — riskier than 46% of all scored CVEsHighest risk
0.00%0.35%0.71%1.06%0.0%0.5%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
.NETUmbraco.Cms

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

An arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute arbitrary code by uploading a crafted PDF file. NOTE: this is disputed by the Supplier because the responsibility for file validation (as shown in the documentation) belongs to the system administrator who is implementing Umbraco CMS in their environment, not to Umbraco CMS itself. The Supplier also states that PDF JavaScript runs in a completely isolated sandbox, not the browser's DOM context, which means that privilege boundaries would not be crossed, a related issue to CVE-2023-49279.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
.NETNuGetUmbraco.Cmsall versionsNo fix

Affected Products

1 product · 1 configurations
Application
umbraco cmsumbraco
1 version
16.3.3

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.Cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    The records we use list no patched version of Umbraco.Cms for CVE-2025-67288. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

  3. Mitigate without a patch

    Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.

Frequently Asked Questions

An arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute arbitrary code by uploading a crafted PDF file. NOTE: this is disputed by the Supplier because the responsibility for file validation (as shown in the documentation) belongs to the system administrator who is implementing Umbraco CMS in their environment, not to Umbraco CMS itself. The Supplier also states that PDF JavaScript runs in a completely isolated sandbox, not the browser's DOM context, which means that privilege boundaries would not be crossed, a related issue to CVE-2023-49279.
O3 Security · Impact-Aware SCA

Is CVE-2025-67288 in your dependencies?

Find it across NuGet, including transitive dependencies.

CVE-2025-67288: Umbraco.Cms RCE (Critical 10)