CVE-2026-35490
CRITICAL9.8EPSS 0.03%changedetection.io Vulnerable to Authentication Bypass via Decorator Ordering
Published: 4/6/2026Modified: 5/20/2026
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 (2)
- PyPI/changedetection-iofrom 0, < 0.54.8
- PyPI/changedetection-iofrom 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 |
References (5)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-35490
- PATCHhttps://github.com/dgtlmoon/changedetection.io
- WEBhttps://github.com/dgtlmoon/changedetection.io/commit/31a760c2147e3e73a403baf6d7de34dc50429c85
- WEBhttps://github.com/dgtlmoon/changedetection.io/releases/tag/0.54.8
- WEBhttps://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-jmrh-xmgh-x9j4