CVE-2026-29038 changedetection.io: Reflected XSS in RSS Tag Error Response

Medium 6.1 Published Updated

Reflected XSS in changedetection.io allows attackers to execute arbitrary JavaScript in victim browsers via the RSS tag endpoint.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-29038?

CVE-2026-29038 is a medium-severity cross-site scripting vulnerability in dgtlmoon changedetection.io, published on 6 Mar 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

changedetection.io is a free open source web page change detection tool. Prior to version 0.54.4, there is a reflected cross-site scripting (XSS) vulnerability identified in the /rss/tag/ endpoint of changedetection.io. The tag_uuid path parameter is reflected 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. This issue has been patched in version 0.54.4.

Weakness: CWE-79

Which versions are affected by CVE-2026-29038?

3 open source packages ship an affected version, including changedetection.io and changedetection-io. It affects 1 product.

PackageAffectedFixed in
changedetection.io PyPIAll versions0.54.4
changedetection-io PyPIAll versions0.54.4
changedetection-io PyPIAll versions0.54.4

Products include Webtechnologies Changedetection.

How do I fix CVE-2026-29038?

Upgrade changedetection.io to 0.54.4 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-29038 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29038 exists.

Sources

Also known as GHSA-8whx-v8qq-pq64, PYSEC-2026-2127.

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