CVE-2026-63570

Loop with unreachable exit condition in Pkcs12Store.GetCertificateChain in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a crafted PKCS#12 file to an application that loads it and requests a key entry's certificate chain to cause a denial of service, in which the call never returns and consumes CPU and memory until an OutOfMemoryException, via certificates whose issuer links form a cycle, for example two certificates whose AuthorityKeyIdentifier extensions each identify the other's public key. This happens because the chain-building loop stops only when no issuer is found or a certificate links to itself, and keeps no record of certificates already visited. The key-identifier links are followed without checking signatures.

Score

CVSS 3.1 7.5 High

Status

Analyzed - 91579145-5d7b-4cc5-b925-a0262ff19630

Published

2026-10-02

Last modified

2026-10-28

Weaknesses

CWE-835

Affected products

• Bc-csharp (Bouncycastle)
• Bc-csharp (Legion Of The Bouncy Castle Inc.)

References

• https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63570
• https://github.com/bcgit/bc-csharp/commit/1b8fad04df4953230c9951c57678ee45c8aead85