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 scri…
Published Apr 9, 2026 · corrected/updated Jul 8, 2026 · juniper junos space · evidence confidence high
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, enables the attacker to execute commands with the target's permissions, including an administrator. This issue affects all versions of Junos Space before 24.1R5 Patch V3.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-21904 is a medium public vulnerability record for juniper junos space. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether juniper junos space is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: juniper/junos space (1.0); juniper/junos space (1.1); juniper/junos space (1.2); juniper/junos space (1.3). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 5.1, EPSS 0.2%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-79. Sources contributing to this record: cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Apr 9, 2026 · NIST NVD
Detected
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, enables the attacker to execute commands with the target's permissions, including an administrator. This issue affects all versions of Junos Space before 24.1R5 Pat
Jul 8, 2026 · NIST NVD
Updated
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, enables the attacker to execute commands with the target's permissions, including an administrator. This issue affects all versions of Junos Space before 24.1R5 Pat
Affected
- cpe juniper/junos space1.0
- cpe juniper/junos space1.1
- cpe juniper/junos space1.2
- cpe juniper/junos space1.3
- cpe juniper/junos space1.4
- cpe juniper/junos space11.1
- cpe juniper/junos space11.2
- cpe juniper/junos space2.0
Sources
- CVE.orgVulnerability recordCVE-2026-21904
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-21904
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-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, enables the attacker to execute commands w
nvd.nist.gov