CVE-2026-63570

7.5

Loop with unreachable exit condition in Pkcs12Store.GetCertificateChain in Legion of the Bouncy Castle Inc

CVSS: 7.5, high high CVSS v3.1
EPSS, next 30 days: 0.2% higher than 11.6% of scored CVEs
Exploitation: No public evidence
Published: 2 Oct 202627 days ago

Description

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.

Details

Vendor: Legion of the Bouncy Castle Inc.
Product: bc-csharp
Weakness: CWE-835 (opens in a new tab)
Status: Analyzed
Updated: 28 Oct 2026
Assigner: 91579145-5d7b-4cc5-b925-a0262ff19630

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References 2

Patches and fixes 2

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Legion of the Bouncy Castle Inc. CVEs

Every Legion of the Bouncy Castle Inc. CVE we hold

Same vendor in what we hold, not a known link between the flaws.

CVE-2026-17507 In Bouncy Castle for Java before 1.86, the MLS implementation (org.bouncycastle.mls) holds RFC 9420's uint32 leaf_index in a signed int,… EPSS 0.4% 7.5, high
CVE-2026-15999 Improper validation of integrity check value in the AES-CCM implementation (CcmParameters and CcmBlockCipher) in Legion of the Bouncy… EPSS 0.2% 7.5, high
CVE-2026-16000 Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc EPSS 0.2% 7.5, high
CVE-2026-16001 Exposure of the message authentication key through the encryption keystream in the stream mode of IesEngine (an IesEngine constructed… EPSS 0.2% 7.5, high
CVE-2026-63566 Memory allocation with excessive size value in the DTLS handshake reassembly (DtlsReliableHandshake, DtlsReassembler) in Legion of the… EPSS 0.4% 7.5, high
CVE-2026-63567 Observable discrepancy in IesEngine.DecryptBlock in Legion of the Bouncy Castle Inc EPSS 0.5% 7.5, high
CVE-2026-63568 Legion of the Bouncy Castle Inc. bc-csharp Allocation of Resources Without Limits or Throttling Vulnerability EPSS 0.4% 7.5, high
CVE-2026-103600 Uncontrolled recursion in the ASN.1 parser (Asn1InputStream, Asn1StreamParser) in Legion of the Bouncy Castle Inc EPSS 0.3% 7.5, high

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Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 29 Oct 2026, not the live upstream state.