{"id":"CVE-2026-40302","aliases":["GHSA-4fxq-2x3x-6xqx","GO-2026-5118"],"url":"https://o3.security/vulnerability/CVE-2026-40302","summary":"zrok has reflected XSS in GitHub OAuth callback via unsanitized refreshInterval error rendering","details":"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.","published":"2026-04-17T20:56:08.368Z","modified":"2026-08-05T03:32:34.302518852Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":{"score":0.00209,"percentile":0.11148,"asOf":"2026-08-05"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/openziti/zrok","fixedVersion":null},{"ecosystem":"Go","name":"github.com/openziti/zrok/v2","fixedVersion":"2.0.1"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/openziti/zrok/releases/tag/v2.0.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40302.json"},{"type":"ADVISORY","url":"https://github.com/openziti/zrok/security/advisories/GHSA-4fxq-2x3x-6xqx"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40302"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-05T03:32:34.302518852Z"}}