Cyber Resilience

CVE-2025-40925

Critical

Published: 20 September 2025

Published
20 September 2025
Modified
15 April 2026
KEV Added
Patch
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 0.0008 22.8th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-40925 is a critical-severity PRNG (CWE-338) vulnerability. Its CVSS base score is 9.1 (Critical).

Operationally, ranked at the 22.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Starch versions 0.14 and earlier generate session ids insecurely. The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come…

more

from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

CWE(s)

Related Threats

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

Affected Assets

Starch
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.

addresses: CWE-338 CWE-340

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

addresses: CWE-338

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

References