CVE-2026-12803

CVE-2026-12803 affects Bouncy Castle for Java prior to 1.85 (and Java LTS prior to 2.73.12). KCCMBlockCipher MAC fails to bind nonce when AAD is absent, enabling cross-nonce AEAD forgery. Impacts confidentiality and integrity as described; CVSS v4.0 base score 8.7 (HIGH). Remediation: upgrade to ...

CVE-2026-12803 KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery)

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...