Riskcovery

CVE-2026-12803

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

State
Published
Severity
8.7 High
Published
Aug 3, 2026
Updated
Aug 3, 2026
Reserved
Jun 21, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
4.08.7 HighCVSS: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:Amberbcorg

Weaknesses

  • CWE-354 Improper Validation of Integrity Check Value

Affected Products

ProductVersions
BC-JAVALegion of the Bouncy Castle Inc.
  • before 1.85Affected
BC-LTS-JAVALegion of the Bouncy Castle Inc.
  • 2.73.0 to before 2.73.12Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.