Steeltoe: TLS private keys written to /tmp with default permissions, never deleted

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.7 · CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-50267: 0.07% estimated exploitation activity in the next 30 days; percentile 0.01 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary When MySQL or PostgreSQL service bindings from VCAPSERVICES include TLS client credentials, the Connectors library writes those credentials to temporary files in Path.GetTempPath() using File.CreateText. On Linux, File.CreateText creates files with mode 0644 (world-readable) under the process umask, and the files are never deleted. The same key material is protected at mode 0400 in /proc/<pid/environ. Impact Any process co-located in the container that runs as a different UID can read the TLS client private key from /tmp and use it to impersonate the application when connecting to the backing database over mutual TLS. Affected configuration - Application is deployed on Cloud Foundry or another environment that populates VCAPSERVICES with a MySQL or PostgreSQL service binding that includes sslKey credentials. - A process running as a different UID shares the container's filesystem. Mitigations If an immediate upgrade is not possible, prevent other processes from running in the…

Published by the source

2 Jul 2026, 20:32 UTC

Last modified by the source

2 Jul 2026, 20:32 UTC

Source last checked

26 Oct 2026, 17:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-rxrh-4j9h-xgg9

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# Patch Next advisory brief: CVE-2026-50267

Advisory: Steeltoe: TLS private keys written to /tmp with default permissions, never deleted
IDs: CVE-2026-50267, GHSA-rxrh-4j9h-xgg9
Record: https://patchnext.com/advisories/cve-2026-50267 (revision 1, source checked 26 Oct 2026, 17:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: steeltoe.configuration.abstractions 4.2.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet steeltoe.configuration.abstractions: affected >= 4.0.0, <= 4.1.0; fixed in 4.2.0

## Suggested inspection (read-only)
- NuGet steeltoe.configuration.abstractions: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on steeltoe.configuration.abstractions.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rxrh-4j9h-xgg9 (GitHub-reviewed advisory GHSA-rxrh-4j9h-xgg9 lists affected ranges: NuGet steeltoe.configuration.abstractions >=4.0.0 <=4.1.0)

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