CVE-2026-59642
Description
In Bouncy Castle for Java before 1.85, CMS AuthenticatedData content not bound to MAC when authAttrs present. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).
Summary dbcve.org
In Bouncy Castle for Java, the CMS AuthenticatedData implementation fails to properly bind the message content to the Message Authentication Code (MAC) when authenticated attributes (authAttrs) are present. This allows attackers to potentially replace or modify the content while keeping a valid MAC, bypassing authentication integrity checks.
Mitigation
Upgrade Bouncy Castle Java library to version 1.85+, LTS 2.73.12+, or the appropriate FIPS version (bcpkix-fips 1.0.12+, 2.0.12+, or 2.1.12+) to resolve the MAC binding vulnerability.