CVE-2026-35571Public exploitNetwork attack vector

Stored XSS via unvalidated navigation link schemes

Published Apr 7, 2026 · Updated Apr 7, 2026

Stored XSS in National Security Agency Emissary before 8.39.0 allows remote authenticated users to execute script via navItems links. The nav.mustache template places each configuration-controlled link value in an href attribute without validating its URL scheme, so a javascript URI remains executable. Administrative access is required to alter navItems, and another authenticated user must click the malicious link; execution then occurs in that user's browser context.

CVSS severity4.8
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in National Security Agency Emissary before 8.39.0 allows remote authenticated users to execute script via navItems links. The nav.mustache template places each configuration-controlled link value in an href attribute without validating its URL scheme, so a javascript URI remains executable. Administrative access is required to alter navItems, and another authenticated user must click the malicious link; execution then occurs in that user's browser context.

The record

CVE
CVE-2026-35571
Published
Apr 7, 2026
Updated
Apr 7, 2026
Vendor
National Security Agency
Product
Emissary
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Apr 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 8.39.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

National Security Agency · Emissaryversion=< 8.39.0

Published CVSS scores

4.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo