# CVE-2026-14570: Crypt::DSA biased random number generation in makerandom

Source: https://junglewise.ai/threats/cve-2026-14570-crypt-dsa-biased-random-number-generation-in-makerandom  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-05. Updated: 2026-07-05  
License: CC BY 4.0 with a link back

CVE-2026-14570 · Severity: info · CVSS 0 · Published 2026-07-05

Crypt::DSA is a Perl library used to generate digital signatures for verifying the authenticity of data. A flaw in how the library generates random numbers means that the secret keys used for these signatures are not truly random. An attacker who observes a small number of signatures can use mathematical techniques to recover the private key, allowing them to forge signatures or impersonate the legitimate owner.

## Quick answers

**Is CVE-2026-14570 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-14570 being exploited in the wild.

**How severe is CVE-2026-14570?** Informational severity, with a CVSS score of 0, published 5 July 2026.

**Which products and versions are affected?** TIMLEGGE (CPAN) Crypt::DSA < 1.22.

**Is there a fix for CVE-2026-14570?** A patch was published on 2026-07-03: Version 1.22 released to fix the bias issue. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-14570 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-14570?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Crypt::DSA::Util::makerandom function, used for generating both the DSA signing nonce (k) and the private key, contains a modulo bias. Specifically, the function forces the high bit of every returned value to be set to ensure an exactly N-bit integer for prime searches. This lack of uniformity results in a fixed top bit, producing insecure values. An attacker who collects a modest number of signatures (potentially hundreds) generated with an affected key can perform a lattice-based attack to recover the full private key. Users should upgrade to version 1.22 and generate new keys, as existing keys generated or used with vulnerable versions are compromised.

## Affected products

- TIMLEGGE (CPAN) Crypt::DSA < 1.22

## Timeline

- 2026-07-03: patched: Version 1.22 released to fix the bias issue.
- 2026-07-05: disclosed: CVE-2026-14570 published.

## References

- [https://cpan.org/modules](https://cpan.org/modules)
- [https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/source/lib/Crypt/DSA/Util.pm](https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/source/lib/Crypt/DSA/Util.pm)
- [https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/changes](https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/changes)
- [https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/diff/TIMLEGGE/Crypt-DSA-1.21](https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/diff/TIMLEGGE/Crypt-DSA-1.21)