{"id":"CVE-2026-50267","aliases":["EUVD-2026-37820","GHSA-rxrh-4j9h-xgg9"],"status":"published","title":"Steeltoe: TLS private keys written to /tmp with default permissions, never deleted","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/\u003cpid\u003e/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`.","severity":{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00065,"percentile":0.00014,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-312","CWE-732"],"published":"2026-06-17T21:57:09Z","modified":"2026-11-08T10:45:15Z","fixes":[{"ecosystem":"NuGet","package":"Steeltoe.Configuration.Abstractions","fixed_in":["4.2.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"NuGet","package":"Steeltoe.Configuration.Abstractions","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"last_affected":"4.1.0"},{"fixed":"4.2.0"}]}]},{"source":"osv","ecosystem":"NuGet","package":"Steeltoe.Configuration.Abstractions","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.2.0"}]}],"versions":["4.0.0","4.1.0"]}],"products":[{"vendor":"steeltoeoss","product":"steeltoe.configuration.abstractions"}],"references":[{"url":"https://github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-rxrh-4j9h-xgg9","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/SteeltoeOSS/Steeltoe/commit/8dd97cc6c4b184121a4bd1f92f9ac16918433471","tags":["x_refsource_MISC","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50267","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-rxrh-4j9h-xgg9"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50267.json","tags":["advisory"]},{"url":"https://github.com/SteeltoeOSS/security-advisories","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-50267","title":"Steeltoe: TLS private keys written to /tmp with default permissions, never deleted","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/\u003cpid\u003e/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`.","status":"published","published":"2026-06-17T21:57:09.043Z","modified":"2026-06-18T19:11:04.674Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-312","CWE-732"],"updated_at":"2026-11-02T14:20:09.098623Z"}],"euvd":[{"id":"EUVD-2026-37820","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/\u003cpid\u003e/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`.","status":"published","published":"2026-06-17T21:57:09Z","modified":"2026-06-18T19:11:04Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:20:36.276608Z"}],"ghsa":[{"id":"GHSA-rxrh-4j9h-xgg9","title":"Steeltoe: TLS private keys written to /tmp with default permissions, never deleted","description":"### Summary\n\nWhen 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/\u003cpid\u003e/environ`.\n\n### Impact\n\nAny 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.\n\n### Affected configuration\n\n- Application is deployed on Cloud Foundry or another environment that populates `VCAP_SERVICES` with a MySQL or PostgreSQL service binding that includes `sslKey` credentials.\n- A process running as a different UID shares the container's filesystem.\n\n### Mitigations\n\nIf an immediate upgrade is not possible, prevent other processes from running in the container under a different UID with access to `/tmp`.","status":"published","published":"2026-07-02T20:32:09Z","modified":"2026-07-02T20:32:10Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-312","CWE-732"],"updated_at":"2026-11-02T14:40:38.48196Z"}],"nvd":[{"id":"CVE-2026-50267","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/\u003cpid\u003e/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`.","status":"published","published":"2026-06-17T23:17:04.59Z","modified":"2026-10-26T11:10:00.157Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-312","CWE-732"],"updated_at":"2026-11-02T14:12:24.544761Z"}],"osv":[{"id":"CVE-2026-50267","title":"Steeltoe: TLS private keys written to /tmp with default permissions, never deleted","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/\u003cpid\u003e/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`.","status":"published","published":"2026-06-17T21:57:09.043Z","modified":"2026-11-08T10:45:15.435839274Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-312","CWE-732"],"updated_at":"2026-11-08T11:04:08.386699Z"},{"id":"GHSA-rxrh-4j9h-xgg9","title":"Steeltoe: TLS private keys written to /tmp with default permissions, never deleted","description":"### Summary\n\nWhen 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/\u003cpid\u003e/environ`.\n\n### Impact\n\nAny 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.\n\n### Affected configuration\n\n- Application is deployed on Cloud Foundry or another environment that populates `VCAP_SERVICES` with a MySQL or PostgreSQL service binding that includes `sslKey` credentials.\n- A process running as a different UID shares the container's filesystem.\n\n### Mitigations\n\nIf an immediate upgrade is not possible, prevent other processes from running in the container under a different UID with access to `/tmp`.","status":"published","published":"2026-07-02T20:32:09Z","modified":"2026-07-02T20:56:33.690158Z","cvss":[{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-312","CWE-732"],"updated_at":"2026-11-02T15:46:56.639206Z"}]}}