CVE-2026-3256

9.8 CRITICAL 0.5% exploit odds No fix listed Crypto

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.5% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2026-02-26 11:59 UTC ReservedThe CVE id was reserved by its CNA
2026-03-28 19:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-29 07:16 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.5% in the next 30 days (EPSS).
Severity: 9.8 CRITICAL (CVSS).
Fix: none linked yet, which raises it.

Details

Published: 2026-03-28 19:16 UTC
Last modified: 2026-06-29 07:16 UTC
Exploit probability: 0.5% · EPSS, next 30 days
Weakness: CWE-338
Record status: Modified

Affected

Ktat http\ ≤ 0.53

Attack profile CVSS 3.1 · 9.8

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-3256.md and follow it. Check whether this project is affected by CVE-2026-3256. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

· More options · Status badge

Download Square Reddit

References

NVD record · CVE.org record