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

Analyzed

AliasesGHSA-mw8m-398g-h89wPYSEC-2026-2125

Published 25-02-2026Last modified 25-02-2026

Vulnerability summary

CVE-2026-27645 is a medium (CVSS 6.1) Cross-site Scripting vulnerability in dgtlmoon changedetection.io. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 42% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk

35/100

0100

Medium · default modelHow is this calculated?

CVSS score

6.1/10

010

Medium · v3.1 (CVE.org)

EPSS score

0.50%

0%100%

Low · +0.06 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits1github

Timeline

25-02-2026
PublishedVulnerability first disclosed.
25-02-2026
Last modifiedVulnerability information updated.

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.