CVE-2026-35490 — changedetection.io has an Authentication Bypass via Decorator Ordering
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()…
Published: 2026-04-07 · CVSS: 9.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7