Umbraco CMS 16
Umbraco CMS 16
The Umbraco CMS 16 reached end of service life on Jun 12, 2026 — Umbraco CMS no longer ships security patches or fixes for it. Our third-party support keeps it safe to run: 24/7 engineers manage issues, remediate vulnerabilities, and help you maintain compliance.
24/7 engineers own your Umbraco CMS 16 incidents end to end.
Mitigation and patch-around guidance when the vendor no longer ships fixes.
Controls evidence and documentation that keep auditors satisfied.
Specifications
- product
- umbraco
- release
- 16
- product Label
- Umbraco CMS
- release Label
- 16
- codename
- lts
- latest Version
- 16.5.1
- release Date
- 2025-06-12
- maintained
- source Url
- https://endoflife.date/umbraco
Lifecycle Dates
- End of Service Life
- Jun 12, 2026
- Last OEM Support
- Mar 12, 2026
OEM vs. 3rd Party Support
See how third-party support compares to the vendor contract for Umbraco CMS 16 — monitoring, break/fix, vulnerability work, operations and compliance, before and after EOSL.
| Feature | OEM Support | 3rd Party Support |
|---|---|---|
| Post-EOSL Support | ||
| Break/Fix Support | Until EOSL | |
| 24/7 Monitoring | ||
| Vulnerability Scanning & Remediation | ||
| Managed Operations | ||
| Procedure & Configuration Review | ||
| Compliance & Audit Documentation | Limited | |
| Discounted Migration to Other Platforms |
Why Choose 3rd Party Support for Umbraco CMS 16?
Vulnerability Remediation
Scanning, mitigation and patch-around guidance for Umbraco CMS 16 when the vendor no longer ships fixes.
Compliance Maintenance
Procedure review, controls evidence and the documentation auditors ask for — maintained continuously, not scrambled at audit time.
24/7 Expert Support
Engineers who know this release monitor, manage and fix issues around the clock — break/fix to managed operations.
Umbraco CMS 16 Support: Frequently Asked Questions
Is the Umbraco CMS 16 still supported?
Umbraco CMS ended support for the Umbraco CMS 16 on Jun 12, 2026 — no more patches or fixes from the vendor. Third-party support keeps it covered: our engineers manage issues, remediate vulnerabilities, and help you maintain compliance for as long as you run it.
When is the Umbraco CMS 16 end of service life (EOSL) date?
Umbraco CMS lists the end of service life for the Umbraco CMS 16 as Jun 12, 2026.
Can I keep using the Umbraco CMS 16 after its EOSL date?
Yes. EOSL means Umbraco CMS stops issuing patches and support — the software itself keeps running. Third-party support covers it from there: issue management, security vulnerability remediation, and the compliance documentation auditors ask for, for as long as you choose to run it.
How much does third-party support for the Umbraco CMS 16 cost?
Typically 40-70% below the OEM maintenance renewal price. Exact pricing depends on quantity, service level and location — request a quote and we respond within 24 hours.
Known Vulnerabilities Affecting Umbraco CMS 16
6 published CVEs affect the Umbraco CMS 16, including 2 rated critical or high severity. Umbraco CMS no longer ships security patches for this release — our engineers provide mitigation guidance, workarounds and hardening support.
| CVE | Severity | CVSS | Published | Summary |
|---|---|---|---|---|
| CVE-2025-67288 | CRITICAL | 10.0 | Dec 22, 2025 | 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 |
| CVE-2026-31834 | HIGH | 7.2 | Mar 10, 2026 | Umbraco is an ASP.NET CMS. From 15.3.1 to before 16.5.1 and 17.2.2, A privilege escalation vulnerability has been identified in Umbraco CMS. Under certain conditions, authenticated backoffice users with permission to manage users, may be able to elevate their privileges due to insufficient authorization enforcement when modifying user group memberships. The affected functionality does not properly validate whether a user has sufficient privileges to assign highly privileged roles. This vulnerabi |
| CVE-2026-46616 | MEDIUM | 5.4 | Jun 10, 2026 | Umbraco is an ASP.NET CMS. Prior to versions 13.14.0 and 17.4.0, some of the Surface Controllers in the CMS provide to support member related operations fail to validate redirect URLs, making Razor templates that derive 'RedirectUrl' from user-controlled query parameters vulnerable to malicious redirect attacks. This issue has been patched in versions 13.14.0 and 17.4.0. |
| CVE-2026-31832 | MEDIUM | 5.4 | Mar 10, 2026 | Umbraco is an ASP.NET CMS. From 14.0.0 to before 16.5.1 and 17.2.2, A broken object-level authorization vulnerability exists in a backoffice API endpoint that allows authenticated users to assign domain-related data to content nodes without proper authorization checks. The issue is caused by insufficient authorization enforcement on the affected API endpoint, whereby via an API call, domains can be set on content nodes that the editor does not have permission to access (either via user group pri |
| CVE-2025-54425 | MEDIUM | 5.3 | Jul 30, 2025 | Umbraco is an ASP.NET CMS. In versions 13.0.0 through 13.9.2, 15.0.0 through 15.4.1 and 16.0.0 through 16.1.0, the content delivery API can be restricted from public access where an API key must be provided in a header to authorize the request. It's also possible to configure output caching, such that the delivery API outputs will be cached for a period of time, improving performance. There's an issue when these two things are used together, where caching doesn't vary by the header that contains |
| CVE-2026-46609 | MEDIUM | 4.6 | Jun 10, 2026 | Umbraco is an ASP.NET CMS. From version 14.0.0 to before version 17.4.0, authenticated users are able to inject HTML into an input field, which is rendered in the confirmation dialog without proper output encoding. This issue has been patched in version 17.4.0. |