What’s Vulnerable › Vulnerabilities

CVE-2026-50267: Steeltoe: TLS private keys written to /tmp with default permissions, never deleted

• Severity: medium (CVSS 4.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-17 · updated 2026-10-26
• Weakness: CWE-312

Description

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Configuration.Abstractions 4.0.0 through 4.1.0, when MySQL or PostgreSQL service bindings from `VCAP_SERVICES` 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`. Steeltoe.Configuration.Abstractions version 4.2.0 patches the issue. If an immediate upgrade is not possible, prevent other processes from running in the container under a different UID with access to `/tmp`.

Affected products

• SteeltoeOSS Steeltoe.Configuration.Abstractions: from 4.0.0, < 4.2.0

References

• https://github.com/SteeltoeOSS/Steeltoe/commit/8dd97cc6c4b184121a4bd1f92f9ac16918433471
• https://github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-rxrh-4j9h-xgg9

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