CVE-2026-12803highCWE-354

CVE-2026-12803: high-severity vulnerability in Legion of the Bouncy Castle Inc. BC-JAVA

KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery)

Published

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.7epss 0.2%
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.
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
Affected products
Legion of the Bouncy Castle Inc. · BC-JAVALegion of the Bouncy Castle Inc. · BC-LTS-JAVA
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