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.
Fix
Public exploits 1
- pvharmo2/gha-lab-ed7a1740c4 PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Patch, vendor advisory and mitigation references on NVD 3
- https://github.com/NationalSecurityAgency/emissary/pull/1286 Patch
- https://github.com/NationalSecurityAgency/emissary/pull/1288 Patch
- https://github.com/NationalSecurityAgency/emissary/security/advisories/GHSA-3g6g-gq4r-xjm9 Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 9.1 · nsaNVD modified 2026-10-26 21:10
Affected (CPE criteria) 1
cpe:2.3:a:nsa:emissary:*:*:*:*:*:*:*:*