CVE-2023-31286 is a medium-severity (CVSS 5.3) CWE-209 vulnerability in Serenity.Net.Core. A fix is available for Serenity.Net.Core — see the affected versions and patch details below.
User account enumeration in Serenity
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-31286.
EPSS Exploitation Probability
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
Serenity.Net.Core.NETSerenity.Net.WebReal-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
An issue was discovered in Serenity Serene (and StartSharp) before 6.7.0. When a password reset request occurs, the server response leaks the existence of users. If one tries to reset a password of a non-existent user, an error message indicates that this user does not exist.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Serenity.Net.Core | all versions | 6.7.0dotnet add package Serenity.Net.Core --version 6.7.0 |
| .NETNuGet | Serenity.Net.Web | all versions | 6.7.0dotnet add package Serenity.Net.Web --version 6.7.0 |
Affected Products
sereneserenitystartsharpserenityDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Serenity.Net.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Serenity.Net.Core to 6.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-31286 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.
Frequently Asked Questions
Is CVE-2023-31286 in your dependencies?
Find it across NuGet, including transitive dependencies.