CVE-2026-21907: Juniper Junos Space

Medium severity, CVSS 5.9. EPSS: 0.2% chance of exploitation in the next 30 days.

A Use of a Broken or Risky Cryptographic Algorithm vulnerability in the TLS/SSL server of Juniper Networks Junos Space allows the use of static key ciphers (ssl-static-key-ciphers), reducing the confidentiality of on-path traffic communicated across the connection. These ciphers also do not support Perfect Forward Secrecy (PFS), affecting the long-term confidentiality of encrypted communications.This issue affects all versions of Junos Space before 24.1R5.

Affected products

• Juniper Junos Space: before 24.1 (fixed in 24.1); version 24.1 only

Published 2026-01-15. Last modified 2026-06-17.