Key points
- The vulnerability affects loopx versions 0.0.1 through 0.4.4.
- Version 0.4.5 patches the issue by correcting Origin checks on read endpoints.
- Attackers can exfiltrate Markdown files and goal registry details without user interaction.
The pip package loopx versions 0.0.1 through 0.4.4 contain a high-severity vulnerability, identified as CVE-2026-108372, according to GitHub advisory GHSA-vx2m-gpq4-8j5q. The issue stems from the `loopx serve-status` command sending an `Access-Control-Allow-Origin: *` header on every response. This configuration permits any website visited by the operator to read unauthenticated endpoints. A patched version, 0.4.5, is now available for installation via pip.
In plain English
When `loopx serve-status` runs, it binds to a fixed loopback port. The advisory states that any webpage the operator visits can use a simple fetch request to read data. This happens without any user interaction or credentials. The flaw exposes read-only paths, including status projections and file contents. Write endpoints remain secure because they correctly check the Origin header. The problem is strictly limited to the read paths.
The background
The vulnerability allows attackers to access `GET /status.json`, which reveals goal IDs, run history, and local absolute paths. If the `--global-registry` flag is used, this covers every project on the machine. Attackers can also fetch the content of any Markdown file inside registered goal repositories. Additionally, the `POST /control-plane/configure-goal/dry-run` route lacks Origin checks entirely, leaking configuration details.
What changes now
Users running loopx must upgrade to version 0.4.5 to resolve CVE-2026-108372. This update removes the permissive CORS header from unauthenticated routes. The fix ensures that cross-origin requests cannot access sensitive local data. Teams should verify their installed version immediately. If the system is below 0.4.5, the risk of data exfiltration remains active while the service is running.
Who needs to act first
Teams usually prioritize systems exposed to web browsers with active `loopx serve-status` processes. Check whether development machines are running vulnerable versions before rolling out updates. Back up configuration files before applying the patch to prevent operational disruption. Test the update in a non-production environment to ensure compatibility with existing workflows. Reduce exposure by stopping the service until the fix is verified.
Background: Data exfiltration
Prevent data exfiltration by restricting user permissions to the minimum necessary for their role. Encrypt sensitive files so stolen data remains unreadable. Monitor outbound network traffic for anomalies. These steps stop most common theft methods without requiring expensive hardware.
Read the full guide: How to Stop Data Exfiltration: Practical Controls That Work
What to do and how to stay safe: loopx
- Identify all systems running loopx versions below 0.4.5 and stop the serve-status service immediately.
- Upgrade the pip package to version 0.4.5 or later once the vendor provides the update.
- Monitor network logs for unexpected cross-origin fetch requests to the loopback port.
- Review browser extensions and visited websites for potential data exfiltration attempts.
Step-by-step guide: Emergency Patching: How to Fix Critical Flaws Without Breaking Systems
General security guidance from the Patch Review newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
Which loopx versions are affected by this vulnerability?
Versions 0.0.1 through 0.4.4 are vulnerable, while version 0.4.5 contains the fix.
Can attackers modify data through this flaw?
No, the write endpoints are correctly Origin-checked and are not affected by this issue.
What data is exposed by the vulnerability?
Attackers can read goal status, local paths, and the contents of Markdown files in repos.
