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Fencer Vulns
high 7.5

CVE-2026-41564 json

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

published 2026-04-23 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-25201

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits
0
none known

Summary

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.

Patch / fix

  • MIK CryptX 0.088
  • libcryptx-perl Debian 13 0.085-1+deb13u1
  • libcryptx-perl Debian 14 0.087-2

debian advisories DEBIAN-CVE-2026-41564

  • perl-CryptX openSUSE Leap 16.0 0.89.0-bp160.1.1
  • perl-CryptX openSUSE Tumbleweed 0.89.0-1.1

opensuse advisories openSUSE-SU-2026:20936-1openSUSE-SU-2026:10773-1

  • perl-cryptx Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 0.088-r0

alpine advisories ALPINE-CVE-2026-41564

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-41564 updated cvss 6.8

perl-cryptx: CryptX: Private key recovery due to predictable pseudo-random number generation after forking

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/DCIT/perl-CryptX/security/advisories/GHSA-24c2-gp6c-24c6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

  • MIK CryptX

Classification

Weakness
  • CWE-335 Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
  • CWE-338 Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.