CVE-2026-42047
HIGHInngest 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…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
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.
Affected Products
inngestinngestDetection & mitigation playbook
Vendor / applianceDetect
Inventory every inngest inngest deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the inngest inngest security patch or hotfix for CVE-2026-42047 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-42047 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-42047. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42047 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-42047 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.