CVE-2026-97873 PUBLISHED

Legacy PBES1 and PKCS#12 PBE iteration count honoured unbounded in the raw JCA provider

Assigner: bcorg
Reserved: 25.09.2026 Published: 03.10.2026 Updated: 03.10.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/U:Amber
CVSS Score: 5.3

Product Status

Vendor Legion of the Bouncy Castle Inc.
Product BC-JAVA
Versions Default: unaffected
  • affected from 0 to 1.86 (excl.)
Vendor Legion of the Bouncy Castle Inc.
Product BC-LTS-JAVA
Versions Default: unaffected
  • affected from 2.73.0 to 2.73.13 (excl.)

Credits

  • Arpan Sharma reporter

References

Problem Types

  • CWE-770 Allocation of Resources Without Limits or Throttling CWE