CVE-2025-30223 (CVSS 9.3): Critical XSS Vulnerability Discovered in Beego Framework

A Cross-Site Scripting (XSS) vulnerability has been identified in the Beego framework, a popular Go framework for building web applications and APIs. This vulnerability, tracked as CVE-2025-30223 (CVSS 9.3), could allow attackers to inject malicious JavaScript code into web pages, potentially compromising user data and sessions.

With over 32,000 stars on GitHub, Beego is widely used to build REST APIs, web apps, and backend services. Its streamlined syntax and developer-friendly abstractions have made it a go-to framework in the Go ecosystem.

“A Cross-Site Scripting (XSS) vulnerability exists in Beego’s RenderForm() function due to improper HTML escaping of user-controlled data,” the advisory states.

At the root of the problem is renderFormField(), a helper function used internally by RenderForm() to dynamically generate input fields. However, this function directly injects user-supplied data into HTML templates—without any HTML escaping.

return fmt.Sprintf(`%v<input%v%v name="%v" type="%v" value="%v"%v>`, 
    label, id, class, name, fType, value, requiredString)

“None of the values (label, id, class, name, value) are properly HTML-escaped… This allows attackers to break out of the attribute context or inject HTML tags directly,” the advisory explains.

To make matters worse, RenderForm() returns template.HTML, a type that explicitly bypasses Go’s automatic escaping mechanisms, amplifying the threat.

Attackers can leverage this vulnerability in two primary ways:

• Attribute Injection: Malicious JavaScript can be smuggled via form field values such as DisplayName, escaping the HTML attribute boundary and executing in the browser.
• Content Injection: In fields like <textarea>, an attacker can insert HTML tags and scripts directly into the page.

“The vulnerability can be exploited to execute JavaScript, steal session cookies, hijack accounts, or inject fake login forms to harvest credentials,” the advisory warns.

This becomes especially dangerous in admin interfaces or user management dashboards, where user-generated data is routinely displayed to privileged users.

Affected and Patched Versions:

• Affected Versions: <= v2.3.5
• Patched Version: v2.3.6

The fix involves explicitly escaping all dynamic values before injecting them into the HTML template. Example mitigation:

// Convert value to string and escape it
valueStr := ""
if value != nil {
    valueStr = template.HTMLEscapeString(fmt.Sprintf("%v", value))
}

// Escape the name and label
escapedName := template.HTMLEscapeString(name)
escapedLabel := template.HTMLEscapeString(label)
escapedType := template.HTMLEscapeString(fType)

return fmt.Sprintf(`%v<input%v%v name="%v" type="%v" value="%v"%v>`, 
    escapedLabel, id, class, escapedName, escapedType, valueStr, requiredString)

“The vulnerability can be fixed by properly escaping all user-provided values before inserting them into HTML,” the developers recommend.

Related Posts:

• CVE-2024-4041: Security Flaw Found in Popular Yoast SEO Plugin – Update Immediately!
• Beware of “How to Fix” Button: New Phishing Emails Trick Users into Executing Malicious Commands
• Beware the Windows Search Scam: Clever Phishing Campaign Exploits User Trust
• Beyond HTML: The Hidden Danger of Phishing in HTTP Response Headers