Quick answers
- Is CVE-2026-103600 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-103600 being exploited in the wild.
- How severe is CVE-2026-103600?
- Informational severity, published 2 October 2026.
- Which products and versions are affected?
- Legion of the Bouncy Castle Inc. BouncyCastle.Cryptography before 2.7.0.
- Is there a fix for CVE-2026-103600?
- Yes: fixed in 2.7.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-103600 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-103600?
- Check whether you run Legion of the Bouncy Castle Inc. BouncyCastle.Cryptography at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 2.7.0
Technical details
The Asn1InputStream and Asn1StreamParser classes in Bouncy Castle recursively parse constructed ASN.1 elements without enforcing a depth limit, allowing an attacker to craft deeply nested structures (approximately 2,000 levels in 8 KB) that exhaust the thread stack and raise an uncatchable StackOverflowException. The vulnerability affects all code paths that parse untrusted ASN.1 data, including X.509 certificates, CRLs, CMS/PKCS#7, PKCS#8/PKCS#12, OCSP, and TLS Certificate messages; the fix introduces a configurable MaxDepth property with a default limit of 32.
Affected products
- Legion of the Bouncy Castle Inc. BouncyCastle.Cryptography before 2.7.0
Timeline
- 2026-10-02: disclosed