CVE-2026-3256 HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids
Attackers can predict session IDs due to weak random seeding, potentially leading to account takeover in applications using this Perl library.
- 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-2026-3256?
CVE-2026-3256 is a critical vulnerability in KTAT HTTP::Session, published on 28 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids.
HTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the high resolution 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.
The distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.
Which versions are affected by CVE-2026-3256?
It affects 1 product.
Products include Ktat Http\.
How do I fix CVE-2026-3256?
No fix has been published for CVE-2026-3256 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-3256 being exploited?
There is no known exploitation of CVE-2026-3256 in the wild and no public exploit code.
Sources
Also known as GHSA-mx9c-4xjq-mhj6.