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.

CVSS v3.1

6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS v3.1

6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS

0.45% chance of exploitation in the next 30 days, 37th percentile

Nuclei

medium · CWE-79

Published

2026-02-25

Proof-of-concept exploits (1)

• advisories/GHSA-mw8m-398g-h89w

Nuclei templates (1)

• projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-27645.yaml

References

• CVE Record
• NVD entry

Related

• CVE-2026-27641
• CVE-2026-27654
• CVE-2026-2764
• CVE-2026-2766
• CVE-2026-27638
• CVE-2026-27695