CVE-2026-40302: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in openziti zrok
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.
AI Analysis
Technical Summary
The vulnerability in openziti zrok (before version 2.0.1) involves improper neutralization of input during web page generation (CWE-79). The proxyUi template engine uses Go's text/template instead of html/template, resulting in no HTML escaping of user input. Specifically, the GitHub OAuth callback handlers embed the attacker-controlled refreshInterval query parameter directly into an error message when time.ParseDuration fails, rendering it unescaped in HTML. This allows an attacker to execute arbitrary JavaScript in the OAuth server's origin after a victim completes the OAuth flow. The issue is resolved in version 2.0.1.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary JavaScript in the context of the OAuth server's origin, potentially leading to information disclosure or session manipulation. The CVSS score is 6.1 (medium severity), indicating a moderate impact with network attack vector, no privileges required, user interaction needed, and both confidentiality and integrity impacts.
Mitigation Recommendations
Upgrade openziti zrok to version 2.0.1 or later, where this vulnerability is patched by switching to the html/template engine that properly escapes HTML content. Since the vendor advisory confirms the fix in 2.0.1, applying this official update fully mitigates the issue.
CVE-2026-40302: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in openziti zrok
Description
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in openziti zrok (before version 2.0.1) involves improper neutralization of input during web page generation (CWE-79). The proxyUi template engine uses Go's text/template instead of html/template, resulting in no HTML escaping of user input. Specifically, the GitHub OAuth callback handlers embed the attacker-controlled refreshInterval query parameter directly into an error message when time.ParseDuration fails, rendering it unescaped in HTML. This allows an attacker to execute arbitrary JavaScript in the OAuth server's origin after a victim completes the OAuth flow. The issue is resolved in version 2.0.1.
Potential Impact
Successful exploitation allows an attacker to execute arbitrary JavaScript in the context of the OAuth server's origin, potentially leading to information disclosure or session manipulation. The CVSS score is 6.1 (medium severity), indicating a moderate impact with network attack vector, no privileges required, user interaction needed, and both confidentiality and integrity impacts.
Mitigation Recommendations
Upgrade openziti zrok to version 2.0.1 or later, where this vulnerability is patched by switching to the html/template engine that properly escapes HTML content. Since the vendor advisory confirms the fix in 2.0.1, applying this official update fully mitigates the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-10T20:22:44.036Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e2a136bdfbbecc59908367
Added to database: 4/17/2026, 9:08:06 PM
Last enriched: 4/17/2026, 9:23:15 PM
Last updated: 4/21/2026, 8:35:12 AM
Views: 30
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