CVE-2026-46409
OpenYak local API: unauthenticated CSRF chain leads to Remote Code Execution
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
OpenYak local API: unauthenticated CSRF chain leads to Remote Code Execution
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.
- Record
CVE-2026-46409- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-94, CWE-306, CWE-346, CWE-352, CWE-942
- Updated
- 2026-11-02
EUVDEUVD-2026-54715
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.
- Record
EUVD-2026-54715- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-46409- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-94, CWE-306, CWE-346, CWE-352, CWE-942
- Updated
- 2026-11-02
OSV
OpenYak local API: unauthenticated CSRF chain leads to Remote Code Execution
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.
- Record
CVE-2026-46409- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - Weakness
- CWE-306, CWE-346, CWE-352, CWE-94, CWE-942
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-46409 is a critical vulnerability (CVSS 9.6) in Openyak, published August 7, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.28%, the 20th percentile. No source names a fixed version.