CVE-2026-35571

Emissary has Stored XSS via Navigation Template Link Injection

MEDIUM
4.8
CVSS Score
Published: April 7, 2026 at 03:26 PM UTC
Updated: October 26, 2026 at 09:10 PM UTC
2 products affected across 2 vendorsEmissaryEmissary

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Severity
MEDIUM4.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 8.38.0
v < 8.39.0
Affected range stops below 8.39.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMExploitMitigationThird Party Advisory
Source: cverecord
https://github.com/NationalSecurityAgency/emissary/security/advisories/GHSA-cpm7-cfpx-3hvp

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.8MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79

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