Risk Letters

Exploited vulnerability

CVE-2026-61500

TLP:CLEAR

Rejetto http_file_server Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

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 admi

Facts

  • Vendor: Rejetto
  • Product: Rejetto HFS
  • CVSS: 9.8
  • EPSS (probability of exploitation within 30 days): 1.9 %
  • First known exploitation: 1 October 2026
  • First seen by Risk Letters: 13 July 2026

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD