CVE-2026-40302

[CVE catalog]

zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, the proxyUi template engine uses Go's text/template (which performs no HTML escaping) instead of html/template. The GitHub OAuth callback handlers in both publicProxy and dynamicProxy embed the attacker-controlled refreshInterval query parameter verbatim into an error message when time.ParseDuration fails, and render that error unescaped into HTML. An attacker can deliver a crafted login URL to a victim; after the victim completes the GitHub OAuth flow, the callback page executes arbitrary JavaScript in the OAuth server's origin. Version 2.0.1 patches the issue.

Severity

Medium · CVSS 6.1CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Published

Apr 17, 2026, 9:16:34 PM UTC

Source

[NVD] · [CVE record]

EPSS

0.21% · Oct 29, 2026

{
  "package_releases": [],
  "fixed_versions": [],
  "distribution_packages": [
    {
      "name": "zrok",
      "ecosystem": "cpe",
      "fixed_version": "2.0.1",
      "provider_source": "nvd"
    },
    {
      "name": "zrok",
      "ranges": [
        {
          "fixed": "2.0.1",
          "introduced": "",
          "last_affected": "",
          "start_excluding": ""
        }
      ],
      "ecosystem": "cpe",
      "provider_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40302",
      "fixed_version": "2.0.1",
      "provider_source": "nvd",
      "provider_record_id": "NVD-CVE-2026-40302",
      "provider_updated_at": "2026-10-26T22:10:00.163"
    }
  ]
}