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.
Severity (CVSS)
| Base score | 9.3 |
|---|---|
| Severity | Critical |
| Version | CVSS 4.0 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| Provided by | CNA |
Weaknesses
- CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
Affected products
| Vendor | Product | Versions |
|---|---|---|
| rejetto | hfs | 3.0.0 to <3.2.1 |
References
- https://github.com/rejetto/hfs/releases/tag/v3.2.1 (release-notes patch)
- https://www.vulncheck.com/advisories/rejetto-hfs-session-forgery-via-predictable-signing-key (third-party-advisory)
Generated from the official CVE List on 14 Jul 2026 07:01 UTC.