CVE-2026-12205

Description

Crypt::DSA versions before 1.21 for Perl reused the nonce across signatures, leading to private-key recovery. Crypt::DSA::sign caches the per-signature nonce material in the Key object without ever clearing it. The first sign() on a Key object picks a nonce, and every later sign() on that same object reuses it, producing an identical "r". Keys used to sign more than once with an affected version should be considered compromised.

CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0029

Probability of exploitation

0.21%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-323 CWE-323

References

Other References

https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.20/source/lib/Crypt/DSA.pm#L47 https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/changes http://www.openwall.com/lists/oss-security/2026/06/15/4

Frequently Asked Questions

What is CVE-2026-12205? +

Crypt::DSA versions before 1.21 for Perl reused the nonce across signatures, leading to private-key recovery. Crypt::DSA::sign caches the per-signature nonce material in the Key object without ever clearing it. The first sign() on a Key object picks a nonce, and every later sign() on that same object reuses it, producing an identical "r". Keys used to sign more than once with an affected version should be considered compromised. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-12205? +

CVE-2026-12205 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0029, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-12205? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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