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

> Attackers with access to the exposed actuator endpoint can read sensitive query-string secrets like tokens and API keys from recorded HTTP exchanges.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-8phw-xrj9-cpqp

## What is CVE-2026-75523?

CVE-2026-75523 is a medium-severity vulnerability in SteeltoeOSS security-advisories, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-75523?

2 open source packages ship an affected version, including Steeltoe.Management.Endpoint.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Steeltoe.Management.Endpoint` | NuGet | All versions | 4.3.0 |
| `Steeltoe.Management.Endpoint` | NuGet | All versions | 4.3.0 |

## How do I fix CVE-2026-75523?

Upgrade Steeltoe.Management.Endpoint to 4.3.0 or later.

## Is CVE-2026-75523 being exploited?

There is no known exploitation of CVE-2026-75523 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-75523 and fix it if it is affected.

What it is: CVE-2026-75523 is a medium-severity vulnerability in SteeltoeOSS security-advisories, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-75523 in the wild and no public exploit code.

Affected packages and fixed versions:
- Steeltoe.Management.Endpoint (NuGet): affected all versions; fixed in 4.3.0
- Steeltoe.Management.Endpoint (NuGet): affected all versions; fixed in 4.3.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-75523/ (Markdown: https://insights.sbomify.com/CVE-2026-75523/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-75523
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75523
- OSV: https://osv.dev/vulnerability/CVE-2026-75523

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-75523/
Summaries are generated and may contain mistakes; the official description above is the record.