CVE-2026-35571 Emissary has Stored XSS via Navigation Template Link Injection

What is CVE-2026-35571?

CVE-2026-35571 is a medium-severity cross-site scripting vulnerability in NationalSecurityAgency emissary, published on 7 Apr 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-79

Which versions are affected by CVE-2026-35571?

2 open source packages ship an affected version, including gov.nsa.emissary:emissary. It affects 1 product.

Products include Nsa Emissary.

How do I fix CVE-2026-35571?

Upgrade gov.nsa.emissary:emissary to 8.39.0 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-35571 being exploited?

There is no known exploitation of CVE-2026-35571 in the wild and no public exploit code.

Other vulnerabilities in NationalSecurityAgency emissary

• CVE-2026-35580 Emissary has GitHub Actions Shell Injection via Workflow Inputs Critical 9.1
• CVE-2026-35582 Emissary has an OS Command Injection via Unvalidated IN_FILE_ENDING / OUT_FILE_ENDING in Executrix High 8.8
• CVE-2021-32094 File upload in n/a High 8.8
• CVE-2021-32096 Cross-site request forgery in n/a High 8.8
• CVE-2021-32095 Missing authorization in n/a High 8.1

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-cpm7-cfpx-3hvp.