CVE-2026-35571: NationalSecurityAgency emissary · Cross-site Scripting
Affects NationalSecurityAgency emissarySource CVE Database V5
Not known to be exploited · CVSS 4.8 Medium : upgrade to 8.39.0 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 8.39.0
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 7 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade emissary and nationalsecurityagency/emissary to 8.39.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| NationalSecurityAgencyemissary | Affected
| Fixed in
|
GitHubnationalsecurityagency/emissarypkg:github/nationalsecurityagency/emissaryOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Emissary to version 8.39.0 or later, where this vulnerability is fixed. Since the fix is included in this version, applying this official update is the recommended remediation. Patch status is not explicitly confirmed beyond the fix in 8.39.0, so verify with the vendor advisory before deployment. No alternative mitigations or temporary fixes are indicated.
Description
CVE-2026-35571 is a stored cross-site scripting (XSS) vulnerability in the NationalSecurityAgency's Emissary product prior to version 8.39.0. The issue arises because Mustache navigation templates interpolate configuration-controlled link values directly into href attributes without validating the URL scheme. An administrator with the ability to modify the navItems configuration can inject javascript: URIs, leading to XSS attacks against other authenticated users of the Emissary web interface. This vulnerability has a medium severity with a CVSS score of 4.8. The vulnerability is fixed in Emissary version 8.39.0.