In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue also affects Bouncy Castle for Java LTS before 2.73.12.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
legion of the bouncy castle inc.:bc-java
legion of the bouncy castle inc.:bc-lts-java
References 3
https://github.com/bcgit/bc-java/commit/ea5970ea9b2fb91d763b904692fd21089ca3e396
91579145-5d7b-4cc5-b925-a0262ff19630
https://github.com/bcgit/bc-java/wiki/CVE-2026-12860
91579145-5d7b-4cc5-b925-a0262ff19630
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012860
91579145-5d7b-4cc5-b925-a0262ff19630