What is CVE-2026-27645?

CVE-2026-27645 is a medium-severity vulnerability in Dgtlmoon Changedetection.io, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-02-25.

How severe is CVE-2026-27645?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Dgtlmoon Changedetection.io

CVE-2026-27645

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-02-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.005 (39.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.000

Affected products

Dgtlmoon Changedetection.io — versions < 0.54.1
Webtechnologies Changedetection

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-mw8m-398g-h89w (Exploit, Vendor Advisory)
github.com/dgtlmoon/changedetection.io/commit/a385c89abf44b52fcfa20c7c6a6dd3047… (Patch)

Frequently asked questions

What is CVE-2026-27645?: CVE-2026-27645 is a medium-severity vulnerability in Dgtlmoon Changedetection.io, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-02-25.
How severe is CVE-2026-27645?: Medium severity. CVSS v3 base score is 6.1 out of 10.