Is CVE-2026-63570 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-63570 being exploited in the wild.

How severe is CVE-2026-63570?

Informational severity, published 2 October 2026.

Which products and versions are affected?

Legion of the Bouncy Castle BouncyCastle.Cryptography before 2.7.0.

Is there a fix for CVE-2026-63570?

Yes: fixed in BouncyCastle.Cryptography 2.7.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-63570 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-63570?

Check whether you run Legion of the Bouncy Castle 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.

CVE-2026-63570: Bouncy Castle .NET infinite loop in certificate chain parsing

CVE-2026-63570 · Severity: info · Published 2026-10-02

Bouncy Castle is a widely-used cryptography library for .NET applications. When an application loads a malformed PKCS#12 file with circular certificate chains, the library becomes stuck in an infinite loop that consumes CPU and memory until the application crashes. An attacker can exploit this by providing a crafted PKCS#12 file to cause a denial of service.

Technologies: Legion of the Bouncy Castle BouncyCastle.Cryptography. Vendors: Legion of the Bouncy Castle.

Quick answers

Is CVE-2026-63570 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-63570 being exploited in the wild.
How severe is CVE-2026-63570?: Informational severity, published 2 October 2026.
Which products and versions are affected?: Legion of the Bouncy Castle BouncyCastle.Cryptography before 2.7.0.
Is there a fix for CVE-2026-63570?: Yes: fixed in BouncyCastle.Cryptography 2.7.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-63570 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-63570?: Check whether you run Legion of the Bouncy Castle 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: BouncyCastle.Cryptography 2.7.0

Technical details

The Pkcs12Store.GetCertificateChain method contains an infinite loop that builds a certificate chain by following AuthorityKeyIdentifier links without tracking visited certificates. When two or more certificates form a cycle by linking to each other's public keys, the loop never terminates and exhausts available memory. The vulnerability requires the ability to supply a crafted PKCS#12 file to an application that loads and processes it.

Affected products

Legion of the Bouncy Castle BouncyCastle.Cryptography before 2.7.0

Timeline

2026-10-02: disclosed
2026-06-19: patched

References

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