CVE-2026-12803 Security Details

CVE ID

CVE-2026-12803

CWE

CWE-354

CVE Description

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.

Published

Aug 3, 2026

CVSS Score & Severity

8.7High

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

EPSS Score

0.174%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Affected Ecosystems

affected

Source

National Vulnerability Database

References

GitHub · CommitPROJECT

GitHub · bcgit/bc-javaPROJECT