CVE-2025-40916
Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha text
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha text
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.
- Record
CVE-2025-40916- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338, CWE-804
- Updated
- 2026-11-02
EUVDEUVD-2025-18387
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.
- Record
EUVD-2025-18387- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-w6w2-2wxg-ggwx
Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for...
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.
- Record
GHSA-w6w2-2wxg-ggwx- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-40916- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338, CWE-804
- Updated
- 2026-11-02
OSV
Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha text
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.
- Record
CVE-2025-40916- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-338, CWE-804
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-40916 is a critical vulnerability (CVSS 9.1) in Gryphon Mojolicious::plugin::captchapng, published June 16, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. No source names a fixed version.
References
metacpan.org/release/GRYPHON/Mojolicious-Plugin-CaptchaPNG-1.04/diff/GRYPHON/Mojolicious-Plugin-CaptchaPNG-1.05/lib/Mojolicious/Plugin/CaptchaPNG.pm
security.metacpan.org/docs/guides/random-data-for-security.html
nvd.nist.gov/vuln/detail/CVE-2025-40916
github.com/advisories/GHSA-w6w2-2wxg-ggwx
cpan.org/modules