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fix: URL validation for dynamicHost (CVE-HSYNC-2026-004) #35

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Merged
monteslu merged 1 commit into from
Feb 12, 2026
Merged

fix: URL validation for dynamicHost (CVE-HSYNC-2026-004) #35

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21 changes: 16 additions & 5 deletions connection.js
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Original file line number Diff line number Diff line change
Expand Up @@ -47,12 +47,23 @@ export async function createHsync(config) {
let dynamicTimeout;

if (dynamicHost && !hsyncSecret) {
const result = await fetch.post(`${dynamicHost}/${hsyncBase}/dyn`, {});
if (dynamicHost.toLowerCase().startsWith('https')) {
hsyncServer = `wss://${result.url}`;
} else {
hsyncServer = `ws://${result.url}`;
// Validate dynamicHost to prevent URL injection/SSRF (CVE-HSYNC-2026-004)
let validatedHost;
let isSecure;
try {
const parsed = new URL(dynamicHost);
// Only allow http/https protocols
if (!['http:', 'https:'].includes(parsed.protocol)) {
throw new Error(`Invalid protocol: ${parsed.protocol}`);
}
isSecure = parsed.protocol === 'https:';
// Reconstruct URL with only origin to strip path/query/fragment
validatedHost = parsed.origin;
} catch (urlErr) {
throw new Error(`Invalid dynamicHost URL: ${urlErr.message}`);
}
const result = await fetch.post(`${validatedHost}/${hsyncBase}/dyn`, {});
hsyncServer = isSecure ? `wss://${result.url}` : `ws://${result.url}`;
hsyncSecret = result.secret;
dynamicTimeout = result.timeout;
}
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