CVE-2023-49274 — Umbraco.CMS
LOWCVE-2023-49274 is a low-severity (CVSS 3.7) Information Exposure vulnerability in Umbraco.CMS. A fix is available for Umbraco.CMS — see the affected versions and patch details below.
Umbraco CMS SMTP misconfiguration exposes potential registered user email
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-49274 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
Umbraco.CMS.NETUmbraco.CMS.NETUmbraco.CMSReal-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
Impact
A user enumeration attack is possible when SMTP is not setup correctly, but reset password is enabled
Explanation of the vulnerability
Two different error messages was shown, based on if the user exists or not when using the forgot password functionality, when the SMTP was configured but do not response.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Umbraco.CMS | ≥ 8.0.0&&< 8.18.10 | 8.18.10dotnet add package Umbraco.CMS --version 8.18.10 |
| .NETNuGet | Umbraco.CMS | ≥ 9.0.0&&< 10.8.1 | 10.8.1dotnet add package Umbraco.CMS --version 10.8.1 |
| .NETNuGet | Umbraco.CMS | ≥ 11.0.0&&< 12.3.4 | 12.3.4dotnet add package Umbraco.CMS --version 12.3.4 |
Detection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update Umbraco.CMS to 8.18.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-49274 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-49274 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-49274. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-49274 in your dependencies?
O3 Security finds CVE-2023-49274 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.