RCE in Nationalsecurityagency Emissary
CVE-2026-35580
Emissary is a P2P based data-driven workflow engine. Prior to 8.39.0, GitHub Actions workflow files contained shell injection points where user-controlled workflow_dispatch inputs were interpolated directly into shell commands via ${{ }} expression syntax. An attacker with repository write access could inject arbitrary shell commands, leading to repository poisoning and supply chain compromise affecting all downstream users. This vulnerability is fixed in 8.39.0.
Vulnerability class: Command Injection (OS Command Injection)
EPSS: 0.006 (43.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Nationalsecurityagency Emissary — versions < 8.39.0
- Nsa Emissary
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-35580?
- CVE-2026-35580 is a critical-severity vulnerability in Nationalsecurityagency Emissary, classified under Command Injection. CVSS score: 9.1/10. Published 2026-04-07.
- How severe is CVE-2026-35580?
- Critical severity. CVSS v3 base score is 9.1 out of 10.