CVE-2025-67288: An arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute arbitrary code by up

This month

CRITICAL 10.0REMOTEDOWNGRADE

CVE-2025-67288 is a critical-severity flaw (CVSS 10.0) affecting umbraco cms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 sa

Why this priority

Critical severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 54%)
CISA exploited list	No
Weakness	CWE-434
Published	2025-12-22
Last modified	2026-07-08

Publisher (CNA): MITRE · Vendor: umbraco

Last updated 2026-07-08 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-12-22 19:15 UTCPublished CVE record published
2026-07-08 17:17 UTCUpdated Record last modified

umbraco umbraco cms DOWNGRADE

Affected: 16.3.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 16.3.3

1. Check installed version

apt-cache policy umbraco-cms || rpm -q umbraco-cms || umbraco-cms --version

2. No fixed release: DOWNGRADE to a release before 16.3.3 (Debian / Ubuntu)

apt-cache madison umbraco-cms sudo apt install umbraco-cms=<VERSION_BEFORE_16.3.3> sudo apt-mark hold umbraco-cms

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list umbraco-cms sudo dnf downgrade umbraco-cms-<VERSION_BEFORE_16.3.3> sudo dnf versionlock add umbraco-cms

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-67288?

umbraco cms: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-67288 being exploited?

CVE-2025-67288 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-67288 affect?

CVE-2025-67288 affects umbraco cms. Severity is critical (CVSS 10.0). 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

How urgent is CVE-2025-67288?

Priority 51/100. Critical severity; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-46616 MEDIUM 5.4 UPGRADE Umbraco is an ASP.NET CMS
CVE-2026-46609 MEDIUM 4.6 UPGRADE Umbraco is an ASP.NET CMS
CVE-2025-66625 MEDIUM 4.9 UPGRADE Umbraco is an ASP.NET CMS
CVE-2021-47776 MEDIUM 5.3 DOWNGRADE Umbraco CMS v8.14.1 contains a server-side request forgery vulnerability that allows attackers to manipulate b
CVE-2024-55488 MEDIUM 6.5 DOWNGRADE A stored cross-site scripting (XSS) vulnerability in Umbraco CMS v14.3.1 allows attackers to execute arbitrary

References

← Back to latest CVEs