CVE-2026-61500: Rejetto HFS < 3.2.1 Session Forgery via Predictable Signing Key
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 servercode configuration feature.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Rejetto HFSto a version that resolves this vulnerability.Fixed in 3.2.1Patch Rejetto HFS < 3.2.1 Session Forgery via Predictable Signing Key
Event History
Frequently Asked Questions
What is the severity of CVE-2026-61500?
CVE-2026-61500 has a critical severity rating of 9.8.
How do I fix CVE-2026-61500?
To fix CVE-2026-61500, upgrade Rejetto HFS to version 3.2.1 or later.
What type of vulnerability is CVE-2026-61500?
CVE-2026-61500 is a session forgery vulnerability caused by a weak random number generator.
What software is affected by CVE-2026-61500?
CVE-2026-61500 affects Rejetto HFS versions 3.0.0 through 3.2.0.
What impact does CVE-2026-61500 have on security?
CVE-2026-61500 allows remote attackers to reconstruct session signing keys and potentially hijack user sessions.