How severe is CVE-2023-37267?

CVE-2023-37267 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-37267?

CVE-2023-37267 affects the following packages: Umbraco.Cms.Infrastructure (NuGet), Umbraco.Cms.Infrastructure (NuGet), Umbraco.Cms.Infrastructure (NuGet), Umbraco.Cms.Web.BackOffice (NuGet), Umbraco.Cms.Web.BackOffice (NuGet), Umbraco.Cms.Web.BackOffice (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2023-37267?

Update Umbraco.Cms.Infrastructure to 10.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-37267 is resolved across your whole dependency graph.

How do I detect CVE-2023-37267 in my NuGet dependencies?

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

How do I mitigate CVE-2023-37267 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2023-37267 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-37267 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-37267?

CVE-2023-37267 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 54th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-37267?

CVE-2023-37267 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-37267 published, and has it been updated?

CVE-2023-37267 was published on July 13, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET

.NET NuGet

Not in CISA KEV

HIGH severity

CVE-2023-37267 — Umbraco.Cms.Infrastructure

HIGHFix: umbraco/Umbraco-CMS@1f26f2c

CVE-2023-37267 is a high-severity (CVSS 7.5) CWE-284 vulnerability in Umbraco.Cms.Infrastructure. A fix is available for Umbraco.Cms.Infrastructure — see the affected versions and patch details below.

Umbraco allows possible Admin-level access to backoffice without Auth under rare conditions

Also known asGHSA-h8wc-r4jh-mg7m

Published

Jul 13, 2023

Updated

Oct 28, 2026

Affected

6 pkgs

Patched

6 / 6

Exploits

None indexed

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

A successful exploit gives an attacker total control of the affected component, not partial access.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-37267.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk

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

6 pkgs affected

.NETUmbraco.Cms.Infrastructure.NETUmbraco.Cms.Infrastructure.NETUmbraco.Cms.Infrastructure.NETUmbraco.Cms.Web.BackOffice.NETUmbraco.Cms.Web.BackOffice.NETUmbraco.Cms.Web.BackOffice

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

Under rare conditions, a restart of Umbraco can allow unauthorized users to gain admin-level permissions.

Impact

An unauthorized user gaining admin-level access and permissions to the backoffice.

Patches

10.6.1, 11.4.2, 12.0.1

Workarounds

Enabling the Unattended Install feature will mean the vulnerability is not exploitable.
Enabling IP restrictions to */install/* and */umbraco/* will limit the exposure to allowed IP addresses.

Affected Packages

6 total 6 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Umbraco.Cms.Infrastructure`	≥ 9.0.0&&< 10.6.1	10.6.1`dotnet add package Umbraco.Cms.Infrastructure --version 10.6.1`
.NETNuGet	`Umbraco.Cms.Infrastructure`	≥ 11.0.0&&< 11.4.2	11.4.2`dotnet add package Umbraco.Cms.Infrastructure --version 11.4.2`
.NETNuGet	`Umbraco.Cms.Infrastructure`	≥ 12.0.0&&< 12.0.1	12.0.1`dotnet add package Umbraco.Cms.Infrastructure --version 12.0.1`
.NETNuGet	`Umbraco.Cms.Web.BackOffice`	≥ 9.0.0&&< 10.6.1	10.6.1`dotnet add package Umbraco.Cms.Web.BackOffice --version 10.6.1`
.NETNuGet	`Umbraco.Cms.Web.BackOffice`	≥ 11.0.0&&< 11.4.2	11.4.2`dotnet add package Umbraco.Cms.Web.BackOffice --version 11.4.2`
.NETNuGet	`Umbraco.Cms.Web.BackOffice`	≥ 12.0.0&&< 12.0.1	12.0.1`dotnet add package Umbraco.Cms.Web.BackOffice --version 12.0.1`

Affected Products

1 product · 3 configurations

Application

umbraco cmsumbraco

≥ 12.0.0 && < 12.0.1

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.Cms.Infrastructure, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Umbraco.Cms.Infrastructure to 10.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-37267 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

Under rare conditions, a restart of Umbraco can allow unauthorized users to gain admin-level permissions. ### Impact An unauthorized user gaining admin-level access and permissions to the backoffice. ### Patches 10.6.1, 11.4.2, 12.0.1 ### Workarounds * Enabling the [Unattended Install](https://docs.umbraco.com/umbraco-cms/reference/configuration/unattendedsettings) feature will mean the vulnerability is not exploitable. * Enabling IP restrictions to `*/install/*` and `*/umbraco/*` will limit the exposure to allowed IP addresses.