CVE-2026-50268
Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Configuration.Encryption 4.0.0 through 4.1.0, 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. Steeltoe.Configuration.Encryption version 4.2.0 patches the issue.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Configuration.Encryption 4.0.0 through 4.1.0, 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. Steeltoe.Configuration.Encryption version 4.2.0 patches the issue.
- Record
CVE-2026-50268- CVSS 3.1
- 1.9 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-256, CWE-327
- Updated
- 2026-11-02
EUVDEUVD-2026-37821
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Configuration.Encryption 4.0.0 through 4.1.0, 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. Steeltoe.Configuration.Encryption version 4.2.0 patches the issue.
- Record
EUVD-2026-37821- CVSS 3.1
- 1.9 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4j9m-h44m-2hv8
Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding
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.
- Record
GHSA-4j9m-h44m-2hv8- CVSS 3.1
- 1.9 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-256, CWE-327
- Updated
- 2026-11-02
NVD
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Configuration.Encryption 4.0.0 through 4.1.0, 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. Steeltoe.Configuration.Encryption version 4.2.0 patches the issue.
- Record
CVE-2026-50268- CVSS 3.1
- 1.9 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-256, CWE-327
- Updated
- 2026-11-02
OSV
Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Configuration.Encryption 4.0.0 through 4.1.0, 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. Steeltoe.Configuration.Encryption version 4.2.0 patches the issue.
- Record
CVE-2026-50268- CVSS 3.1
- 1.9 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-256, CWE-327
- Updated
- 2026-11-02
OSVGHSA-4j9m-h44m-2hv8
Steeltoe: OAEP setting silently selects PKCS#1 v1.5 padding
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.
- Record
GHSA-4j9m-h44m-2hv8- CVSS 3.1
- 1.9 Low
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-256, CWE-327
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
Steeltoe.Configuration.EncryptionNuGet |
4.0.0 to 4.1.0 | 4.2.0 |
Steeltoe.Configuration.EncryptionNuGet |
4.0.0 up to 4.2.0, plus listed versions 4.1.0 |
4.2.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-50268 is a low vulnerability (CVSS 1.9) in Steeltoeoss Steeltoe.configuration.encryption, published June 17, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.05%, the 0th percentile. Fixed in Steeltoe.Configuration.Encryption 4.2.0.
References
github.com/SteeltoeOSS/security-advisories/security/advisories/GHSA-4j9m-h44m-2hv8
nvd.nist.gov/vuln/detail/CVE-2026-50268