Legion of the Bouncy Castle Bouncy Castle for Java/Bouncy Castle for Java LTS prior 1.86/2.73.13 PBES1 javax.crypto.EncryptedPrivateKeyInfo.getKeySpec iteration

Summaryinfo

A vulnerability described as problematic has been identified in Legion of the Bouncy Castle Bouncy Castle for Java and Bouncy Castle for Java LTS. This impacts the function javax.crypto.EncryptedPrivateKeyInfo.getKeySpec of the component PBES1. The manipulation results in iteration. This vulnerability is cataloged as CVE-2026-97873. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic has been found in Legion of the Bouncy Castle Bouncy Castle for Java and Bouncy Castle for Java LTS. Affected is the function javax.crypto.EncryptedPrivateKeyInfo.getKeySpec of the component PBES1. The manipulation with an unknown input leads to a iteration vulnerability. CWE is classifying the issue as CWE-834. The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed. This is going to have an impact on availability. CVE summarizes:

In Bouncy Castle for Java before 1.86, the raw JCA provider's legacy PBES1 (PKCS#5 scheme 1) and PKCS#12 PBE families ran their password-based key derivation with an iteration count taken from untrusted input without bounding it, so a small input could dictate an arbitrary amount of work before anything could be verified. The AlgorithmParameters implementations (PKCS12PBE and its object identifier aliases, and PBKDF1) accepted any count from an encoded PKCS12PBEParams or PBEParameter, narrowing a value beyond the int range with intValue(), and every Cipher, Mac and SecretKeyFactory in these families derived with whatever count it was given, including one decoded by another provider's AlgorithmParameters, as when javax.crypto.EncryptedPrivateKeyInfo.getKeySpec() decrypts a PKCS#12 PBE-protected private key with BC. Both the parameter parse and the derivations now reject a negative or over-limit count under the org.bouncycastle.pbe.max_iteration_count property (default 10,000,000) that already bounded PBKDF2 (CVE-2026-17508), and the parse rejects a count beyond the int range rather than narrowing it. This issue also affects Bouncy Castle for Java LTS before 2.73.13.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-97873 since 09/25/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 1.86 or 2.73.13 eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• Legion of the Bouncy Castle

Name

• Bouncy Castle for Java
• Bouncy Castle for Java LTS

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