What is CVE-2026-21904?

CVE-2026-21904 is a medium-severity vulnerability in Juniper Networks Junos Space, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-04-09.

How severe is CVE-2026-21904?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Juniper Networks Junos Space

CVE-2026-21904

An Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Juniper Networks Junos Space allows an attacker to inject script tags in the list filter field that, when visited by another user, e…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (12.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Juniper Networks Junos Space — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

kb.juniper.net/JSA106003 (vendor-advisory)

Frequently asked questions

What is CVE-2026-21904?: CVE-2026-21904 is a medium-severity vulnerability in Juniper Networks Junos Space, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-04-09.
How severe is CVE-2026-21904?: Medium severity. CVSS v3 base score is 6.1 out of 10.