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CVE-2026-63570

high

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

Vendor / product: Bouncycastle — bc-csharp

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
7.5
7.5 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-10-02 08:17
Modified: 2026-10-28 13:23
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-10-28 13:34 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

bouncycastle / bc-csharp <2.7.0

Weakness classification (CWE)

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63570
Patch / mitigation: https://github.com/bcgit/bc-csharp/commit/1b8fad04df4953230c9951c57678ee45c8aead85
Patch / mitigation: https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63570

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-28 13:34 UTC · record ↗

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