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.
https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9012816
https://github.com/bcgit/bc-java/commit/6d9e4bbaee9409713ada167e5f901554cbb084ac
Published: 2026-08-03
Updated: 2026-08-03
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Severity: Critical
Base Score: 8.7
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
Severity: High