CVE-2026-22813CWE-79

Malicious website can execute commands on the local system through XSS in the OpenCode web UI

Critical · published January 12, 2026

CVSS v4.0
9.4
EPSS
1%
Percentile
59.4
In the wild
Unconfirmed
What it is

OpenCode is an open source AI coding agent. The markdown renderer used for LLM responses will insert arbitrary HTML into the DOM. There is no sanitization with DOMPurify or even a CSP on the web interface to prevent JavaScript execution via HTML injection. This means controlling the LLM response for a chat session gets JavaScript execution on the http://localhost:4096 origin. This vulnerability is fixed in 1.1.10.

The record
Technical detail
CVSS v4.0
9.4 · CRITICAL
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
EPSS
0.00905 · 59.4th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-01-12T22:52Z
EPSS history
Timeline
  • 12 JAN 22:52Z
    Malicious website can execute commands on the local system through XSS in the OpenCode web UI
    cvelistv5