Vulnerability Description
In Bouncy Castle for Java before 1.85, KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery). This issue also affects Bouncy Castle for Java LTS before 2.73.12.
Related Weaknesses (CWE)
References
- https://github.com/bcgit/bc-java/commit/697794413ebf7bc5e3fce609a707826ba52981af
- https://github.com/bcgit/bc-java/commit/7d79aa76e984da85f2a541cae8ba2ae56e1713bc
- https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012803
FAQ
What is CVE-2026-12803?
CVE-2026-12803 is a documented vulnerability. In Bouncy Castle for Java before 1.85, KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery). This issue also affects Bouncy Castle for Java LTS before 2.73.12.
How severe is CVE-2026-12803?
CVSS scoring is not yet available for CVE-2026-12803. Check NVD for updates.
Is there a patch for CVE-2026-12803?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.