CVE-2025-40925 Starch versions 0.14 and earlier generate session ids insecurely
Insecure session ID generation in Starch allows attackers to predict IDs and potentially take over user accounts.
- 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-2025-40925?
CVE-2025-40925 is a critical vulnerability in BLUEFEET Starch, published on 20 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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 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.
Which versions are affected by CVE-2025-40925?
How do I fix CVE-2025-40925?
No fix has been published for CVE-2025-40925 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-40925 being exploited?
There is no known exploitation of CVE-2025-40925 in the wild and no public exploit code.
Sources
Also known as GHSA-q46q-p96m-rvh8.