CVE-2026-12852 PUBLISHED

In Bouncy Castle for Java before 1.85, MLS wire decoder allocates attacker-declared opaque length before bounds check.

• Alex Gaynor in collaboration with Claude and Anthropic Research reporter

• https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012852
• https://github.com/bcgit/bc-java/commit/a747038bb5bbd5e29fb2b7607ab38af1fd8d1790

• CWE-789 Memory Allocation with Excessive Size Value CWE