Vulnerability Description
Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can observe encrypted messages of known or chosen content to forge ciphertexts with valid authentication tags, via messages encrypted without associated data. The cause is that the G1 block, which binds the nonce, the message length and the parameter flags into the CBC-MAC, was processed only when associated data was present. Without associated data the tag was a CBC-MAC of the plaintext alone, independent of the nonce. Only applications that use KCcmBlockCipher directly and supply no associated data are affected.
Related Weaknesses (CWE)
References
- https://github.com/bcgit/bc-csharp/commit/b01e9e6c0e231b90867fbaf03bf148bde6f9cc
- https://github.com/bcgit/bc-csharp/wiki/CVE-2026-16000
FAQ
What is CVE-2026-16000?
CVE-2026-16000 is a documented vulnerability. Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can observe encrypted messages o...
How severe is CVE-2026-16000?
CVSS scoring is not yet available for CVE-2026-16000. Check NVD for updates.
Is there a patch for CVE-2026-16000?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.