# CVE-2026-46409

## Summary

- **CVE ID:** CVE-2026-46409
- **Severity:** CRITICAL
- **CVSS Score:** 9.6 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H)
- **CWE:** CWE-94, CWE-306, CWE-346, CWE-352, CWE-942
- **Published:** Aug 7, 2026
- **Last Modified:** Aug 11, 2026

## Description

OpenYak is a local-first agent runtime for reliable tool-using models, with a desktop workspace built on top. Prior to version 1.1.3, the OpenYak desktop backend binds an HTTP API to `127.0.0.1:<random port>` (commonly 19141) without server-side Origin validation, loopback authentication, or Content-Type enforcement, and with a wildcard CORS policy. Any webpage a user visits while OpenYak is running can issue cross-origin requests to this local server — the browser acts as a proxy into loopback, bypassing OS-level network isolation. Chained, this lets a malicious page execute arbitrary shell commands on the host (RCE) via the build agent with `permission_presets.bash=true`, shut down the service, and exfiltrate chat history and account PII — with no user interaction beyond opening the page. Version 1.1.3 patches the issue.

## Affected Products

- openyak — openyak (< 1.1.3)

## References

- [CNA](https://github.com/openyak/openyak/security/advisories/GHSA-ccxp-q2w5-27jw)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.36%
- **EPSS Percentile:** 29.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._