Improper Validation of Integrity Check Value Affecting bouncycastle.cryptography package, versions [,2.7.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DOTNET-BOUNCYCASTLECRYPTOGRAPHY-20537016
- published6 Oct 2026
- disclosed2 Oct 2026
Introduced: 2 Oct 2026
NewCVE-2026-16001 (opens in a new tab)How to fix?
Upgrade BouncyCastle.Cryptography to version 2.7.0 or higher.
Overview
Affected versions of this package are vulnerable to Improper Validation of Integrity Check Value in the stream-mode IesEngine processing path in crypto/src/crypto/engines/IesEngine.cs. An attacker can forge shorter ciphertexts that the recipient accepts as authentic by observing one encrypted message with known plaintext and reusing the recovered keystream to derive the MAC key for shorter messages. This affects static-key IES sessions without a block cipher, where the MAC key is derived from a message-length-dependent offset behind the keystream and a valid ciphertext-plus-tag pair can be constructed for a different message.