CVE-2026-12816 PUBLISHED

IESEngine stream-mode MAC forgery via length-dependent KDF split

Assigner: bcorg
Reserved: 21.06.2026 Published: 03.08.2026 Updated: 03.08.2026

In Bouncy Castle for Java before 1.85, IESEngine stream-mode MAC forgery via length-dependent KDF split. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber
CVSS Score: 8.7

Product Status

Vendor Legion of the Bouncy Castle Inc.
Product BC-JAVA
Versions Default: unaffected
  • affected from 0 to 1.85 (excl.)
Vendor Legion of the Bouncy Castle Inc.
Product BC-LTS-JAVA
Versions Default: unaffected
  • affected from 2.73.0 to 2.73.12 (excl.)

Credits

  • Alex Gaynor in collaboration with Claude and Anthropic Research reporter

References

Problem Types

  • CWE-354 Improper Validation of Integrity Check Value CWE