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CVE-2026-16001

CVE.org · Published

Historical CVEsJSONAI instructions

Record status
Published
Identifier year (not publication year)
2026
Source publication
Source updated
Imported by cveboard
Source snapshot
cve_2026-10-24_midnight_baseline ·

Plain text

CNA source text (English)

IesEngine stream-mode MAC forgery via length-dependent KDF split

Exposure of the message authentication key through the encryption keystream in the stream mode of IesEngine (an IesEngine constructed without a block cipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker who has observed one encrypted message with known plaintext to forge shorter messages of their choosing that the recipient accepts as authentic, via a crafted ciphertext and MAC tag, because the MAC key was taken from the key derivation output directly after a keystream as long as the message, while the derivation input depends only on the static key pair and fixed parameters. The keystream revealed by that one message therefore contains the MAC key for every sufficiently shorter message.

Scoped product and version facts

Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.

Exploitation unknown; this catalogue does not assess exploitation.

bc-csharp

Vendor
Legion of the Bouncy Castle Inc.
Product
bc-csharp
Platforms
Unknown
Default status
unaffected
Package
BouncyCastle.Cryptography
Package collection
https://www.nuget.org/packages/BouncyCastle.Cryptography
bc-csharp · Scoped product and version facts
Version (version)Status (status)Version scheme (versionType)Exclusive end (lessThan)Inclusive end (lessThanOrEqual)Status changes (at → status)
0affectedsemver2.7.0UnavailableNone listed