CVE-2026-61500

CRITICAL

Rejetto HFS < 3.2.1 Session Forgery via Predictable Signing Key

Title source: cna
STIX 2.1

Description

Rejetto HFS 3.0.0 through 3.2.0 derives its session-cookie signing key from the non-cryptographic Math.random() generator and discloses outputs of the same generator to unauthenticated clients during login. A remote attacker can collect a small number of login responses, reconstruct the generator's state, recover the signing key, and forge a valid administrator session cookie, leading to full administrative access and remote code execution via the server_code configuration feature.

References (2)

Core 2
Core References
Patch release-notes patch
Release Notes
https://github.com/rejetto/hfs/releases/tag/v3.2.1

Scores

CVSS v3 9.8
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-338
Status published
Products (1)
rejetto/hfs 3.0.0 - 3.2.1
Published Jul 13, 2026
Tracked Since Jul 13, 2026