CVE-2026-40302

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.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/openziti/zrok/releases/tag/v2.0.1	Release Notes
https://github.com/openziti/zrok/security/advisories/GHSA-4fxq-2x3x-6xqx	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:netfoundry:zrok:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-04-17 21:16

Updated : 2026-06-17 10:44

NVD link : CVE-2026-40302

Mitre link : CVE-2026-40302

CVE.ORG link : CVE-2026-40302

JSON object : View

Products Affected

netfoundry

zrok

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-116

Improper Encoding or Escaping of Output

{"id": "CVE-2026-40302", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-40302", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-04-18T03:07:00.447331Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.1, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.7, "exploitabilityScore": 2.8}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "openziti", "product": "zrok", "versions": [{"status": "affected", "version": "< 2.0.1"}]}]}], "published": "2026-04-17T21:16:34.997", "references": [{"url": "https://github.com/openziti/zrok/releases/tag/v2.0.1", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/openziti/zrok/security/advisories/GHSA-4fxq-2x3x-6xqx", "tags": ["Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-79"}, {"lang": "en", "value": "CWE-116"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-06-17T10:44:58.150", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:netfoundry:zrok:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "70C6F018-6D34-4A75-A49D-A795B0A5B056", "versionEndExcluding": "2.0.1"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}