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.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://github.com/bcgit/bc-csharp/commit/0c7a6dfd64c4a479577e35a728a766721b79aba7 Patch
- https://github.com/bcgit/bc-csharp/commit/7c0ed15f9783c9595b1a53f3900136461fd944f4 Patch
- https://github.com/bcgit/bc-csharp/wiki/CVE-2026-63575 Patch, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.1 · bouncycastleNVD modified 2026-10-28 14:41
Affected (CPE criteria) 1
cpe:2.3:a:bouncycastle:bc-csharp:*:*:*:*:*:*:*:*