CVE-2026-35580 Emissary
| Affected software | Emissary |
|---|---|
| Severity | 9.1 Critical CVSS 3.1 |
| Fixed in | 8.39.0 |
| Weakness | Command injection (CWE-77) |
| Published | 7 Apr 2026 |
| Updated | 26 Oct 2026 |
Description
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.
Exploitation status
No public exploit
No exploit has been reported in the sources we check. The 1 repository below are public GitHub repositories with fewer than 5 stars.
Exploitation status
- CISA KEV not listed
- VulnCheck KEV not listed
- CISA Vulnrichment exploitation: none
- Indexed PoC 1 indexed, none at 5+ stars
- EPSS 0.58% chance in 30 days
| Index | Artifact | Stars | First seen |
|---|---|---|---|
| GitHub PoC | Security-research lab: controlled reproduction of GHSA-3g6g-gq4r-xjm9 / CVE-2026-35580 (GitHub Actions workflow_dispatch input shell injection) against a pinned snapshot of NationalSecurityAgency/emissary | 2026-09-05 |
Waratek protection
Waratek has a rule that blocks attacks on this vulnerability.
- Protection full Process
- Action available security rule
- Review automated Inferred
- Record active
| Decided by | A vulnerability class already blocked by an ARMR security rule |
|---|---|
| Finding | Protected by Waratek's ARMR command-injection security rule, which blocks this class of attack at the JVM level without a rule written for this CVE specifically. The CVE's weakness is CWE-77: Command Injection. |
| Candidate fix | https://github.com/NationalSecurityAgency/emissary/pull/1286 : a pull request: the change under review |
How to mitigate CVE-2026-35580
Upgrade Emissary to 8.39.0 or later. Until you can, Waratek RASP blocks exploitation with its process rule. It runs inside the Java application, with no code changes.
Affected software and releases
Maven packages
Affected and fixed versions, from OSV.dev| Package | Introduced | Fixed | Last affected |
|---|---|---|---|
gov.nsa.emissary:emissary |
0 | 8.39.0 |
unbounded |
References
Timeline
Timeline
| Published | 2026-04-07 | By the CVE Program. |
|---|---|---|
| NVD record modified | 2026-10-26 | NVD's own last-modified date for this record. |