CVE-2026-27645 PoC — changedetection.io Vulnerable to Reflected XSS in RSS Single Watch Error Response

Source

https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-27645.yaml

Associated Vulnerability

Title: changedetection.io Vulnerable to Reflected XSS in RSS Single Watch Error Response (CVE-2026-27645)
Description:changedetection.io is a free open source web page change detection tool. In versions prior to 0.54.1, the RSS single-watch endpoint reflects the UUID path parameter directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the browser parses and executes injected JavaScript. Version 0.54.1 contains a fix for the issue.

Description

changedetection.io < 0.54.1 contains a stored XSS caused by unescaped reflection of UUID path parameter in RSS single-watch endpoint, letting remote attackers execute JavaScript in victim's browser, exploit requires victim to visit crafted URL.

File Snapshot

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