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CVE-2026-635787.1HighCWE-770

CVE-2026-63578: Unbounded PBE iteration count when decrypting PKCS#8 private keys

Legion of the Bouncy Castle Inc. · bc-csharp

Fixed in 2.7.0 · Affected: Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.4%probability of exploitation in the next 30 days
32nd percentile
050100

Higher than 32% of scored CVEs

7.1HighCVSS 4.0
LowHigh

DescriptionCVE.org

Allocation of resources without limits in password-based private-key decryption (PbeUtilities.GenerateCipherParameters) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply an encrypted private key, such as a PKCS#8 EncryptedPrivateKeyInfo or "ENCRYPTED PRIVATE KEY" PEM file, to cause a denial of service through CPU exhaustion via an iteration count close to 2^31, because the count is taken from the unauthenticated algorithm parameters without an upper bound and the key derivation runs before the password or the data can be checked. PKCS#5 PBES1 and PBES2 (PBKDF2), the PKCS#12 PBE algorithms and CMS password recipients (CmsPbeKey) are affected. Loading PKCS#12 files with Pkcs12Store is covered by CVE-2026-63572, and a zero or negative count with the PKCS#12 algorithms by CVE-2026-63575.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

  • Legion of the Bouncy Castle Inc. · bc-csharpbefore 2.7.0

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

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Exploitation
Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV
Not listed
Public check
No public nuclei template
Published
October 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-63578 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References