CVE-2026-63572 PUBLISHED

Unbounded MAC and bag-decryption iteration counts when loading PKCS#12 files

Assigner: bcorg
Reserved: 16.07.2026 Published: 02.10.2026 Updated: 02.10.2026

Allocation of resources without limits in PKCS#12 keystore loading (Pkcs12Store.Load) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can supply a PKCS#12 (PFX) file to cause a denial of service through CPU exhaustion via an iteration count close to 2^31 in the file's MacData or in the PBE parameters of an encrypted SafeContents or shrouded key bag, because the counts are taken from the file without an upper bound and the key derivation runs before the MAC or the password can be checked. A zero or negative count is covered by CVE-2026-63575. Pkcs12Utilities.ConvertToDefiniteLength is also affected.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.1

Product Status

Vendor Legion of the Bouncy Castle Inc.
Product bc-csharp
Versions Default: unaffected
  • affected from 0 to 2.7.0 (excl.)

References

Problem Types

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

Impacts

  • Denial of Service (CPU exhaustion)