Vulnerability · Published Apr 7, 2026 · Assigned by GitHub_M
CVE-2026-35490changedetection.io has an Authentication Bypass via Decorator Ordering
Critical 9.8
In plain English
A critical-severity incorrect authorization in changedetection.io from dgtlmoon. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | changedetection-io | 0.54.8 | GHSA-jmrh-xmgh-x9j4 |
| PyPI | changedetection-io | 0.54.8 | PYSEC-2026-28 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| dgtlmoon | changedetection.io | < 0.54.8 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H