CVE-2026-35580: Nsa Emissary

Critical severity, CVSS 9.1. EPSS: 0.7% chance of exploitation in the next 30 days.

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.

Affected products

• Nsa Emissary: from 5.10.0, up to and including 8.38.0

Published 2026-04-07. Last modified 2026-06-17.