What is CVE-2026-35571?

CVE-2026-35571 is a medium-severity vulnerability in Nationalsecurityagency Emissary, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-04-07.

How severe is CVE-2026-35571?

Medium severity. CVSS v3 base score is 4.8 out of 10.

XSS in Nationalsecurityagency Emissary

CVE-2026-35571

Emissary is a P2P based data-driven workflow engine. Prior to 8.39.0, Mustache navigation templates interpolated configuration-controlled link values directly into href attributes without URL scheme validation. An administrator who could modify the navItems configuration could inject javascript: URIs, enabling stored cross-site scripting (XSS) against other authenticated users viewing the Emissary web interface. This vulnerability is fixed in 8.39.0.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (7.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

Affected products

Nationalsecurityagency Emissary — versions < 8.39.0
Nsa Emissary

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Third Party Advisory, Mitigation)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-35571?: CVE-2026-35571 is a medium-severity vulnerability in Nationalsecurityagency Emissary, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-04-07.
How severe is CVE-2026-35571?: Medium severity. CVSS v3 base score is 4.8 out of 10.