GHSA-4J9M-H44M-2HV8

Vulnerability from github – Published: 2026-07-02 20:32 – Updated: 2026-07-02 20:32
VLAI
Summary
Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding
Details

Summary

Configuring 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.

Impact

Operators 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.

Migration note

Existing {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.

Severity
1.9 (Low)
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.1.0"
      },
      "package": {
        "ecosystem": "NuGet",
        "name": "Steeltoe.Configuration.Encryption"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.2.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-50268"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-256",
      "CWE-327"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-02T20:32:21Z",
    "nvd_published_at": "2026-06-17T23:17:04Z",
    "severity": "LOW"
  },
  "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.",
  "id": "GHSA-4j9m-h44m-2hv8",
  "modified": "2026-07-02T20:32:21Z",
  "published": "2026-07-02T20:32:21Z",
  "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"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding"
}



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