CVE-2026-35490
changedetection.io Vulnerable to Authentication Bypass via Decorator Ordering
Description
changedetection.io is a free open source web page change detection tool. Prior to 0.54.8, the @login_optionally_required decorator is placed before (outer to) @blueprint.route() instead of after it. In Flask, @route() must be the outermost decorator because it registers the function it receives. When the order is reversed, @route() registers the original undecorated function, and the auth wrapper is never in the call chain. This silently disables authentication on these routes. This vulnerability is fixed in 0.54.8.
How to fix CVE-2026-35490
To remediate CVE-2026-35490, upgrade the affected package to a fixed version below.
- —upgrade to 0.54.8 or later
- —upgrade to 0.54.8 or later
Is CVE-2026-35490 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0, < 0.54.8
- from 0, < 0.54.8
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |