Allocation of resources without limits in PKCS#12 keystore loading (Pkcs12Store.Load) in Legion of the Bouncy Castle Inc. (CVE-2026-63572)
A vulnerability in Legion of the Bouncy Castle Inc. bc-csharp before version 2.7.0 allows an attacker to cause a denial of service by supplying a specially crafted PKCS#12 (PFX) file with an extremely high iteration count in the MacData or PBE parameters. This leads to excessive CPU usage during key derivation before authentication checks occur. The issue affects Pkcs12Store.Load and Pkcs12Utilities.ConvertToDefiniteLength functions.
AI Analysis
Technical Summary
The vulnerability (CVE-2026-63572) exists in the PKCS#12 keystore loading functionality of Legion of the Bouncy Castle Inc. bc-csharp library versions prior to 2.7.0. An attacker who can provide a malicious PKCS#12 file can trigger resource exhaustion by setting an iteration count close to 2^31 in the file's MacData or encrypted SafeContents or shrouded key bag parameters. The iteration counts are used without an upper bound, causing the key derivation process to consume excessive CPU resources before the MAC or password is verified. This results in a denial of service condition. The vulnerability also affects the Pkcs12Utilities.ConvertToDefiniteLength function. A related issue with zero or negative counts is tracked separately under CVE-2026-63575.
Potential Impact
Successful exploitation allows an unauthenticated attacker to cause a denial of service via CPU exhaustion by supplying a crafted PKCS#12 file with a very high iteration count. This can disrupt applications or services that load such keystores, potentially impacting availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid loading untrusted PKCS#12 files or implement application-level limits on iteration counts during keystore loading if possible.
Allocation of resources without limits in PKCS#12 keystore loading (Pkcs12Store.Load) in Legion of the Bouncy Castle Inc. (CVE-2026-63572)
Description
A vulnerability in Legion of the Bouncy Castle Inc. bc-csharp before version 2.7.0 allows an attacker to cause a denial of service by supplying a specially crafted PKCS#12 (PFX) file with an extremely high iteration count in the MacData or PBE parameters. This leads to excessive CPU usage during key derivation before authentication checks occur. The issue affects Pkcs12Store.Load and Pkcs12Utilities.ConvertToDefiniteLength functions.
CVSS v4.0
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability (CVE-2026-63572) exists in the PKCS#12 keystore loading functionality of Legion of the Bouncy Castle Inc. bc-csharp library versions prior to 2.7.0. An attacker who can provide a malicious PKCS#12 file can trigger resource exhaustion by setting an iteration count close to 2^31 in the file's MacData or encrypted SafeContents or shrouded key bag parameters. The iteration counts are used without an upper bound, causing the key derivation process to consume excessive CPU resources before the MAC or password is verified. This results in a denial of service condition. The vulnerability also affects the Pkcs12Utilities.ConvertToDefiniteLength function. A related issue with zero or negative counts is tracked separately under CVE-2026-63575.
Potential Impact
Successful exploitation allows an unauthenticated attacker to cause a denial of service via CPU exhaustion by supplying a crafted PKCS#12 file with a very high iteration count. This can disrupt applications or services that load such keystores, potentially impacting availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid loading untrusted PKCS#12 files or implement application-level limits on iteration counts during keystore loading if possible.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-v54c-wxx6-mjh6
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63572"]
- Database Specific Severity
- HIGH
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abfeeb7a43b0b3b89e5609f
Added to database: 10/02/2026, 17:49:43 UTC
Last enriched: 10/02/2026, 18:20:54 UTC
Last updated: 10/02/2026, 19:45:56 UTC
Views: 3
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