What is CVE-2026-21907?

CVE-2026-21907 is a medium-severity vulnerability in Juniper Junos_space, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 5.9/10. Published 2026-01-15.

How severe is CVE-2026-21907?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Vulnerability in Juniper Junos_space

CVE-2026-21907

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 communica…

Vulnerability class: POODLE (CVE-2014-3566)

EPSS: 0.002 (7.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Juniper Junos_space — versions 24.1
Juniper Networks Junos Space — versions 0

Weakness classification (CWE)

CWE-327 — Use of a Broken or Risky Cryptographic Algorithm

References

sirt@juniper.net (vendor-advisory, Vendor Advisory)
sirt@juniper.net (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21907?: CVE-2026-21907 is a medium-severity vulnerability in Juniper Junos_space, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 5.9/10. Published 2026-01-15.
How severe is CVE-2026-21907?: Medium severity. CVSS v3 base score is 5.9 out of 10.