CVE-2026-21907 Junos Space: TLS/SSL server supports use of static key ciphers (ssl-static-key-ciphers)

What is CVE-2026-21907?

CVE-2026-21907 is a high-severity vulnerability in Juniper Junos Space, published on 15 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-327

Which versions are affected by CVE-2026-21907?

It affects 1 product.

Products include Juniper Junos Space.

How do I fix CVE-2026-21907?

No fix has been published for CVE-2026-21907 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-21907 being exploited?

There is no known exploitation of CVE-2026-21907 in the wild and no public exploit code.

Other vulnerabilities in Juniper Junos Space

• CVE-2014-3412 Command injection in n/a Critical 10.0
• CVE-2014-3413 Hardcoded credentials in n/a Critical 9.8
• CVE-2016-1265 Junos Space: privilege escalation vulnerabilities in Junos Space Critical 9.8
• CVE-2017-10622 Junos Space: Authentication bypass vulnerability Critical 9.8
• CVE-2016-4926 Auth bypass in n/a Critical 9.8

All Juniper Junos Space vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-65rw-m955-9596.