CryptX versions before 0.088 for Perl do not reseed the Crypt::PK PRNG state after forking.

The Crypt::PK::RSA, Crypt::PK::DSA, Crypt::PK::DH, Crypt::PK::ECC, Crypt::PK::Ed25519 and Crypt::PK::X25519 modules seed a per-object PRNG state in their constructors and reuse it without fork detection. A Crypt::PK::* object created before `fork()` shares byte-identical PRNG state with every child process, and any randomized operation they perform can produce identical output, including key generation. Two ECDSA or DSA signatures from different processes are enough to recover the signing private key through nonce-reuse key recovery.

This affects preforking services such as the Starman web server, where a Crypt::PK::* object loaded at startup is inherited by every worker process.
Advisories

No advisories yet.

Fixes

Solution

Upgrade to CryptX 0.088 or later, or apply the upstream patch. Applying the fix does not retroactively protect keys that may already have been exposed. On an affected version, any private key used with or generated by a Crypt::PK::* object created before `fork()` should be assessed for rotation.


Workaround

No workaround given by the vendor.

History

Thu, 23 Apr 2026 08:00:00 +0000

Type Values Removed Values Added
Description CryptX versions before 0.088 for Perl do not reseed the Crypt::PK PRNG state after forking. The Crypt::PK::RSA, Crypt::PK::DSA, Crypt::PK::DH, Crypt::PK::ECC, Crypt::PK::Ed25519 and Crypt::PK::X25519 modules seed a per-object PRNG state in their constructors and reuse it without fork detection. A Crypt::PK::* object created before `fork()` shares byte-identical PRNG state with every child process, and any randomized operation they perform can produce identical output, including key generation. Two ECDSA or DSA signatures from different processes are enough to recover the signing private key through nonce-reuse key recovery. This affects preforking services such as the Starman web server, where a Crypt::PK::* object loaded at startup is inherited by every worker process.
Title CryptX versions before 0.088 for Perl do not reseed the Crypt::PK PRNG state after forking
Weaknesses CWE-335
CWE-338
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published:

Updated: 2026-04-23T09:33:41.857Z

Reserved: 2026-04-21T12:45:20.132Z

Link: CVE-2026-41564

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-23T08:16:01.243

Modified: 2026-04-23T08:16:01.243

Link: CVE-2026-41564

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses