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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/bcgit/bc-csharp/commit/1b8fad04df4953230c9951c57678ee45c8aead85	Patch
https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63570	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*

History

28 Oct 2026, 13:23

Type	Values Removed	Values Added
References	~~() https://github.com/bcgit/bc-csharp/commit/1b8fad04df4953230c9951c57678ee45c8aead85 -~~	() https://github.com/bcgit/bc-csharp/commit/1b8fad04df4953230c9951c57678ee45c8aead85 - Patch
References	~~() https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63570 -~~	() https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63570 - Patch, Vendor Advisory
CPE		cpe:2.3:a:bouncycastle:bc-csharp::::::::
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.5
First Time		Bouncycastle bc-csharp Bouncycastle

02 Oct 2026, 08:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-02 08:17

Updated : 2026-10-28 13:23

NVD link : CVE-2026-63570

Mitre link : CVE-2026-63570

CVE.ORG link : CVE-2026-63570

JSON object : View

Products Affected

bouncycastle

bc-csharp

CWE

CWE-835

Loop with Unreachable Exit Condition ('Infinite Loop')

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