CVE-2026-61500: Rejetto HFS

Critical severity, CVSS 9.8. EPSS: 1% chance of exploitation in the next 30 days.

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.

Affected products

• Rejetto HFS: from 3.0.0, before 3.2.1 (fixed in 3.2.1)

Published 2026-07-13. Last modified 2026-07-15.