CVEvulnerability

CVE-2026-16000

8.7 HIGH Published 2026-10-02 Modified 2026-10-27 Official page ↗
Status
Analyzed
Published
2026-10-02
Last modified
2026-10-27
Assigner
91579145-5d7b-4cc5-b925-a0262ff19630
CVSS 4.0 (91579145-5d7b-4cc5-b925-a0262ff19630)
8.7 HIGH — 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weaknesses
CWE-325

Description

Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can observe encrypted messages of known or chosen content to forge ciphertexts with valid authentication tags, via messages encrypted without associated data. The cause is that the G1 block, which binds the nonce, the message length and the parameter flags into the CBC-MAC, was processed only when associated data was present. Without associated data the tag was a CBC-MAC of the plaintext alone, independent of the nonce. Only applications that use KCcmBlockCipher directly and supply no associated data are affected.

Affected configurations

• bouncycastle bc-csharp (< 2.7.0)

Related

Weakness · CWE (1)

  • CWE-325 Missing Cryptographic Step weakness

References