Denial of Service in ASN.1 Parser for Bouncy Castle .NET Products
CVE-2026-103600

8.7HIGH

Key Information:

Vendor

Legion Of The Bouncy Castle Inc.

Status
Bc-csharp
Vendor
CVE Published:
2 October 2026

What is CVE-2026-103600?

An uncontrolled recursion vulnerability exists in the ASN.1 parser of Bouncy Castle .NET, specifically in the Asn1InputStream and Asn1StreamParser components. This can allow unauthenticated remote attackers to create a denial of service by sending specially crafted ASN.1 encoded data containing deeply nested elements. The recursion without depth limitation can lead to exhaustion of the thread stack, resulting in a StackOverflowException that terminates the process. Any application that processes untrusted ASN.1 data—such as handling X.509 certificates, CMS/PKCS#7 messages, and OCSP responses—is at risk of being affected.

Affected Version(s)

bc-csharp 0 < 2.7.0

References

https://github.com/bcgit/bc-csharp/wiki/CVE-2026-103600
vendor-advisory
https://github.com/bcgit/bc-csharp/commit/89c81b0da7fe11c...
patch
https://github.com/bcgit/bc-csharp/commit/b99f4e3dcea05b5...
patch

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Yt
.