by Kastro
Paper/Archive/CVE-2026-35580

CVE-2026-35580

NationalSecurityAgency emissary — Emissary has GitHub Actions Shell Injection via Workflow Inputs

EPSS 0.6%CVSS 9.1
critical.is priorityof 100
37
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 47.0.470 × 209.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
emissary< 8.39.0–CNA

Scores by source

GitHub_M (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/NationalSecurityAgency/emissary/security/advisories/GHSA-3g6g-gq4r-xjm9refgithub.com/NationalSecurityAgency/emissary/pull/1286refgithub.com/NationalSecurityAgency/emissary/pull/1288