CVE-2025-40916 Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha text
Attackers can bypass captcha protections because the plugin uses a weak random number generator for captcha text and noise.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-40916?
CVE-2025-40916 is a critical vulnerability in GRYPHON Mojolicious::Plugin::CaptchaPNG, published on 16 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2025-40916?
How do I fix CVE-2025-40916?
No fix has been published for CVE-2025-40916 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-40916 being exploited?
There is no known exploitation of CVE-2025-40916 in the wild and no public exploit code.
Sources
Also known as GHSA-w6w2-2wxg-ggwx.