Legion of the Bouncy Castle bc-csharp up to 2.6.x PKCS#12 Key Derivation Pkcs12Store.Load infinite loop

Summaryinfo

A vulnerability classified as problematic has been found in Legion of the Bouncy Castle bc-csharp up to 2.6.x. The impacted element is the function Pkcs12Store.Load of the component PKCS#12 Key Derivation. Performing a manipulation results in infinite loop. This vulnerability was named CVE-2026-63575. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Legion of the Bouncy Castle bc-csharp up to 2.6.x. This affects the function Pkcs12Store.Load of the component PKCS#12 Key Derivation. The manipulation with an unknown input leads to a infinite loop vulnerability. CWE is classifying the issue as CWE-835. The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. This is going to have an impact on availability. The summary by CVE is:

Loop with unreachable exit condition in the PKCS#12 key derivation (Pkcs12ParametersGenerator) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a PKCS#12 (PFX) file, or a PKCS#8 encrypted private key that uses a PKCS#12 password-based encryption algorithm, to cause a denial of service through CPU exhaustion via an iteration count of zero or below, because the derivation loop ran until its counter equalled the count, so for such a count it wrapped through about 2^32 iterations before the MAC or the password could be checked. A 75-byte PFX file with a negative MacData iteration count kept Pkcs12Store.Load busy for many minutes.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-63575 since 07/17/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 2.7.0 eliminates this vulnerability.

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Productinfo

Vendor

• Legion of the Bouncy Castle

Name

• bc-csharp

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6

CPE 2.3info

• 🔒
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CPE 2.2info

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