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-20537000
- published6 Oct 2026
- disclosed2 Oct 2026
Introduced: 2 Oct 2026
NewCVE-2026-63574 (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 through SignatureSubpacketsReader.ReadPacket and UserAttributeSubpacketsReader.ReadPacket in the OpenPGP subpacket parsers. An attacker can trigger denial of service by supplying a crafted OpenPGP public key, certificate, or signature with a five-octet subpacket length header that makes the parser allocate a huge buffer before reading any subpacket data. The parsers trusted the declared body length and only rejected values above int.MaxValue, so a few bytes of input could force multi-gigabyte allocation attempts and exhaust memory or raise OutOfMemoryException during parsing.