CVE-2025-32016 — Microsoft.Identity.Web
MEDIUMCVE-2025-32016 is a medium-severity (CVSS 4.7) CWE-532 vulnerability in Microsoft.Identity.Web. A fix is available for Microsoft.Identity.Web — see the affected versions and patch details below.
Microsoft Identity Web Exposes Client Secrets and Certificate Information in Service Logs
Exploitation Status
No confirmed exploitation observed yet
- 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-2025-32016.
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-2025-32016 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 377,636 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
Microsoft.Identity.Web.NETMicrosoft.Identity.AbstractionsReal-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
What kind of vulnerability is it? Who is impacted?
Description: This vulnerability affects confidential client applications, including daemons, web apps, and web APIs. Under specific circumstances, sensitive information such as client secrets or certificate details may be exposed in the service logs of these applications. Service logs are intended to be handled securely.
Impact: The vulnerability impacts service logs that meet the following criteria:
- Logging Level: Logs are generated at the information level.
- Credential Descriptions: containing:
- Local file paths with passwords.
- Base64 encoded values.
- Client secret.
Additionally, logs of services using Base64 encoded certificates or certificate paths with password credential descriptions are also affected if the certificates are invalid or expired, regardless of the log level. Note that these credentials are not usable due to their invalid or expired status.
If your service logs are handled securely, you are not impacted.
Otherwise, the following table shows when you can be impacted
| Log Level Information for Microsoft.Identity.Web | Invalid Certificate | |
|---|---|---|
| One of the ClientCredentials credential description has a CredentialSource = Base64Encoded or (CredentialSource = Path) | Impacted | Impacted |
| One of the ClientCredentials credential description is a Client secret (CredentialSource = ClientSecret) | Impacted | Not impacted |
| Other credential descriptions | Not Impacted | Not Impacted |
Patches
Has the problem been patched? What versions should users upgrade to? To mitigate this vulnerability, update to Microsoft.Identity.Web 3.8.2 or Microsoft.Identity.Abstractions 9.0.0.
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading? You can work around the issue in the following ways:
-
Ensure that service logs are handled securely and access to logs is restricted
-
Don’t use
LogLevel = Informationfor the Microsoft.Identity.Web namespace
Recommendation for production environment
Avoid using ClientCredentials with CredentialDescriptions which CredentialSource is ClientSecret, or Base64Encoded, or Path. Rather use certificate from KeyVault or a certificate store, or Federation identity credential with Managed identity.
References
Are there any links users can visit to find out more?
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Microsoft.Identity.Web | ≥ 3.2.0&&< 3.8.2 | 3.8.2dotnet add package Microsoft.Identity.Web --version 3.8.2 |
| .NETNuGet | Microsoft.Identity.Abstractions | ≥ 7.1.0&&< 9.0.0 | 9.0.0dotnet add package Microsoft.Identity.Abstractions --version 9.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Microsoft.Identity.Web, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Microsoft.Identity.Web to 3.8.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-32016 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-2025-32016 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-32016. 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-2025-32016 in your dependencies?
O3 Security finds CVE-2025-32016 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.