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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

• CVE-2023-37267: 0.71% estimated exploitation activity in the next 30 days; percentile 53.78 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

13 Jul 2023, 17:02 UTC

Last modified by the source

4 Nov 2023, 05:02 UTC

Source last checked

26 Oct 2026, 17:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h8wc-r4jh-mg7m

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# Patch Next advisory brief: CVE-2023-37267

Advisory: Umbraco allows possible Admin-level access to backoffice without Auth under rare conditions
IDs: CVE-2023-37267, GHSA-h8wc-r4jh-mg7m
Record: https://patchnext.com/advisories/cve-2023-37267 (revision 1, source checked 26 Oct 2026, 17:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: umbraco.cms.web.backoffice 12.0.1, 11.4.2, 10.6.1; umbraco.cms.infrastructure 12.0.1, 11.4.2, 10.6.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet umbraco.cms.web.backoffice: affected >= 9.0.0, < 10.6.1; >= 11.0.0, < 11.4.2; >= 12.0.0, <= 12.0.0; fixed in 10.6.1, 11.4.2, 12.0.1
- NuGet umbraco.cms.infrastructure: affected >= 9.0.0, < 10.6.1; >= 11.0.0, < 11.4.2; >= 12.0.0, <= 12.0.0; fixed in 10.6.1, 11.4.2, 12.0.1

## Suggested inspection (read-only)
- NuGet umbraco.cms.web.backoffice: check the installed version with your package manager.
- NuGet umbraco.cms.infrastructure: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on umbraco.cms.web.backoffice, umbraco.cms.infrastructure.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-h8wc-r4jh-mg7m (GitHub-reviewed advisory GHSA-h8wc-r4jh-mg7m lists affected ranges: NuGet umbraco.cms.infrastructure >=9.0.0 =11.0.0 =12.0.0 =9.0.0 =11.0.0 =12.0.0 <=12.0.0)

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