{"id":"GHSA-4j9m-h44m-2hv8","summary":"Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding","details":"### Summary\n\nConfiguring `encrypt:rsa:algorithm=OAEP` does not enable OAEP encryption. Due to an incorrect BouncyCastle transformation string, the `OAEP` setting selects PKCS#1 v1.5, which is the same algorithm as the `DEFAULT` setting.\n\n### Impact\n\nOperators who configure `encrypt:rsa:algorithm=OAEP` to obtain CCA2-secure padding receive PKCS#1 v1.5 instead. Currently, `Decrypt()` is called only against operator-controlled configuration data, so no exploitable path exists, but any future code path that exposes a decryption oracle would be Bleichenbacher-vulnerable despite the `OAEP` setting.\n\n### Migration note\n\nExisting `{cipher}` values produced under the broken `OAEP` setting were encrypted with PKCS#1 v1.5. The fix makes `OAEP` use actual OAEP padding, so those values will fail to decrypt after upgrading. Re-encrypt all affected `{cipher}` values after upgrading.","aliases":["CVE-2026-50268"],"modified":"2026-07-02T20:45:13.203644944Z","published":"2026-07-02T20:32:21Z","database_specific":{"cwe_ids":["CWE-256","CWE-327"],"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-07-02T20:32:21Z","nvd_published_at":"2026-06-17T23:17:04Z"},"references":[{"type":"WEB","url":"https://github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-4j9m-h44m-2hv8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50268"},{"type":"WEB","url":"https://github.com/SteeltoeOSS/Steeltoe/commit/6cfee5cccddf8f9a31de69b0ca5ccdd771b73e5b"},{"type":"PACKAGE","url":"https://github.com/SteeltoeOSS/security-advisories"}],"affected":[{"package":{"name":"Steeltoe.Configuration.Encryption","ecosystem":"NuGet","purl":"pkg:nuget/Steeltoe.Configuration.Encryption"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.0.0"},{"fixed":"4.2.0"}]}],"versions":["4.0.0","4.1.0"],"database_specific":{"last_known_affected_version_range":"\u003c= 4.1.0","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-4j9m-h44m-2hv8/GHSA-4j9m-h44m-2hv8.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N"}]}