Memory Allocation with Excessive Size 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-20537001
- published6 Oct 2026
- disclosed2 Oct 2026
Introduced: 2 Oct 2026
NewCVE-2026-63566 (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 Memory Allocation with Excessive Size Value due to unbounded DTLS handshake reassembly in DtlsReliableHandshake and DtlsReassembler. A remote unauthenticated DTLS peer can exhaust memory by sending crafted handshake fragments with a large declared 24-bit message length, causing the reassembly buffer for each pending pre-auth handshake message to be allocated before the handshake is authenticated.