Cyber Resilience

CVE-2025-40916

Critical

Published: 16 June 2025

Published
16 June 2025
Modified
15 April 2026
KEV Added
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Patch
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CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0028 52.1th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-40916 is a critical-severity PRNG (CWE-338) vulnerability. Its CVSS base score is 9.1 (Critical).

Operationally, ranked in the top 47.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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.

CWE(s)
CWE-338CWE-804

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

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CaptchaPNG
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AT-5 Contacts with Security Groups and Associations
addresses: CWE-338

Security associations share details on cryptographically weak PRNGs, helping avoid their implementation in security-critical functions.

SC-12 Cryptographic Key Establishment and Management
addresses: CWE-338

Cryptographic key management standards require cryptographically strong PRNGs for key material, blocking use of weak generators.

References