CVE-2026-3255 HTTP::Session2 versions before 1.12 for Perl may generate weak session ids using the rand() function
Attackers can predict session IDs due to weak random number generation, potentially leading to account takeover.
- 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-2026-3255?
CVE-2026-3255 is a medium-severity vulnerability in TOKUHIROM HTTP::Session2, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function.
The HTTP::Session2 session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. 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.
HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.
Which versions are affected by CVE-2026-3255?
It affects 1 product.
Products include Tokuhirom Http\.
How do I fix CVE-2026-3255?
No fix has been published for CVE-2026-3255 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-3255 being exploited?
There is no known exploitation of CVE-2026-3255 in the wild and no public exploit code.
Other vulnerabilities in TOKUHIROM HTTP::Session2
Sources
Also known as GHSA-2p7f-7xjf-8q9q.