Information disclosure in Bouncy Castle

Published: 2020-11-08
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2020-26939
Exploitation vector Network
Public exploit N/A
Vulnerable software
The Bouncy Castle Crypto Package For Java
Universal components / Libraries / Libraries used by multiple products

Vendor Legion of the Bouncy Castle Inc.

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Information disclosure

EUVDB-ID: #VU48199

Risk: Medium


CVE-ID: CVE-2020-26939


Exploit availability:


The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to observable differences in behavior to error inputs within the org.bouncycastle.crypto.encodings.OAEPEncoding component in Legion of the Bouncy Castle BC. A remote attacker can obtain sensitive information about a private exponent by sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder. This causes the application to throw an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.


Install updates from vendor's website.

Vulnerable software versions

The Bouncy Castle Crypto Package For Java: 1.50 - 1.60

Fixed software versions

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?