CVE-2026-75523 is a medium-severity (CVSS 5.9) Information Exposure vulnerability in Steeltoe.Management.Endpoint. A fix is available for Steeltoe.Management.Endpoint — see the affected versions and patch details below.
Steeltoe.Management.Endpoint: HttpExchanges URI masking leaks query-string secrets
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-2026-75523.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-75523 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,189 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
Steeltoe.Management.EndpointReal-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
Summary
Steeltoe's /actuator/httpexchanges endpoint records and displays request URIs after passing them through MaskedUri. The masking only covers the UserInfo portion of the URI (inline user:password@host credentials) and does not inspect the query string. With IncludeQueryString enabled by default, any secrets carried in query strings (for example: OAuth tokens, password-reset tokens, signed-URL signatures, API keys) are returned verbatim in the uri field of the response and written to logs at DEBUG level.
Impact
Any caller who can reach /actuator/httpexchanges can receive full request URIs from prior traffic, including any secrets those URIs contained in their query strings. Applications with DEBUG-level logging enabled for the Steeltoe.Management.Endpoint.Actuators.HttpExchanges namespace also write these URIs to their application logs.
Affected configuration
httpexchangesis explicitly added to the actuator exposure list (Management:Endpoints:Web:Exposure:Include). It is not included by default.- The application handles requests that carry secrets in query strings, such as OAuth callbacks, signed URLs, or password-reset links.
- DEBUG logging is enabled for
Steeltoe.Management.Endpoint.Actuators.HttpExchanges(log exposure only).
Mitigations
If an immediate upgrade is not possible:
- Remove
httpexchangesfrom the actuator exposure list, or restrict it behind authentication. - Set
Management:Endpoints:HttpExchanges:IncludeQueryStringtofalseto strip query strings from recorded exchanges entirely.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Steeltoe.Management.Endpoint | all versions | 4.3.0dotnet add package Steeltoe.Management.Endpoint --version 4.3.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Steeltoe.Management.Endpoint, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Steeltoe.Management.Endpoint to 4.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-75523 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2026-75523 in your dependencies?
Find it across NuGet, including transitive dependencies.