What is CVE-2025-40916?

CVE-2025-40916 is a critical-severity vulnerability in Gryphon Mojolicious::plugin::captchapng, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 9.1/10. Published 2025-06-16.

How severe is CVE-2025-40916?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Gryphon Mojolicious::plugin::captchapng

CVE-2025-40916

Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha. That version uses the built-in rand() function for generating the captcha text as well as image noise, which is insecure.

EPSS: 0.003 (25.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Gryphon Mojolicious::plugin::captchapng — versions 1.05

Weakness classification (CWE)

CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
CWE-804

References

9b29abf9-4ab0-4765-b253-1875cd9b441e
9b29abf9-4ab0-4765-b253-1875cd9b441e
9b29abf9-4ab0-4765-b253-1875cd9b441e
9b29abf9-4ab0-4765-b253-1875cd9b441e

Frequently asked questions

What is CVE-2025-40916?: CVE-2025-40916 is a critical-severity vulnerability in Gryphon Mojolicious::plugin::captchapng, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 9.1/10. Published 2025-06-16.
How severe is CVE-2025-40916?: Critical severity. CVSS v3 base score is 9.1 out of 10.