CVE-2026-63572
Unbounded MAC and bag-decryption iteration counts when loading PKCS#12 files
- State
- Published
- Severity
- 7.1 High
- Published
- Oct 2, 2026
- Updated
- Oct 2, 2026
- Reserved
- Jul 16, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.1 High | 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 | bcorg |
Weaknesses
- CWE-770 Allocation of Resources Without Limits or Throttling
Affected Products
| Product | Versions |
|---|---|
bc-csharpLegion of the Bouncy Castle Inc. |
|
References
- https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63572vendor-advisory
- https://github.com/bcgit/bc-csharp/commit/7c0ed15f9783c9595b1a53f3900136461fd944f4patch
- https://github.com/bcgit/bc-csharp/commit/c00fc018fca89c077c64dd2a2a2eb00ae7d97241patch
- https://github.com/bcgit/bc-csharp/commit/54ea0b179ee627027829b44c45d6dd32e575bd67patch
- https://github.com/bcgit/bc-csharp/commit/34a7c05f719c91c024f285c6b420d3c00f8019ddpatch
- https://github.com/bcgit/bc-csharp/commit/b57165ecb7790ecea08273b219d52d80c12990e4patch
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