Summary
Tilt: Missing authentication on the network-exposed Tilt HUD server
The Tilt HUD HTTP server exposes state-changing and sensitive-read endpoints with no authentication. When the HUD is bound to a non-loopback address, a network attacker can trigger the developer's pre-defined Tiltfile resources, tamper with Tiltfile arguments, read full engine state including the session token, and reach the Tilt apiserver through a token-attaching proxy.
Details
The HUD server registers its handlers on a gorilla/mux router with no authenticating middleware. The cookieWrapper helper emits the Tilt-Token cookie but never validates it, and is attached only to the static-asset prefix.
Conditions for exploitation
- Affected version in
>= 0.20.8, <= 0.37.3. - HUD bound to a non-loopback address (
tilt up --host 0.0.0.0, orTILT_HOSTset). - Network reachability to the listener (default port
10350).
Not affected
- The default loopback-only bind is not reachable from the network.
Workarounds
Use the default loopback bind (omit --host, unset TILT_HOST) and ensure nothing else proxies to localhost:10350. No complete workaround short of upgrading for non-loopback deployments.
Impact
An unauthenticated network caller can force any developer-defined resource to run on the host as the tilt user (choosing which and when, not the command text), set arbitrary Tiltfile arguments, disclose the session token and full engine state, and invoke apiserver resources via the loopback-token proxy. Because tilt up runs with the developer's privileges and credentials, the impact reaches the developer's environment and cluster.
A critical operation is accessible without requiring any authentication. Typical impact: any user can invoke the privileged function.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-55884? CVE-2026-55884 is a critical-severity missing authentication for critical function vulnerability in github.com/tilt-dev/tilt (go), affecting versions >= 0.20.8, <= 0.37.3. It is fixed in 0.37.4. A critical operation is accessible without requiring any authentication.
- Which versions of github.com/tilt-dev/tilt are affected by CVE-2026-55884? github.com/tilt-dev/tilt (go) versions >= 0.20.8, <= 0.37.3 is affected.
- Is there a fix for CVE-2026-55884? Yes. CVE-2026-55884 is fixed in 0.37.4. Upgrade to this version or later.
- Is CVE-2026-55884 exploitable, and should I be worried? Whether CVE-2026-55884 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-55884 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-55884? Upgrade
github.com/tilt-dev/tiltto 0.37.4 or later.