Auth bypass in Dgtlmoon Changedetection.io
CVE-2026-35490
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (48.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Dgtlmoon Changedetection.io — versions < 0.54.8
- Webtechnologies Changedetection
Weakness classification (CWE)
References
- github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-jmrh-xmgh-x9j4 (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-35490?
- CVE-2026-35490 is a critical-severity vulnerability in Dgtlmoon Changedetection.io, classified under Incorrect Authorization. CVSS score: 9.8/10. Published 2026-04-07.
- How severe is CVE-2026-35490?
- Critical severity. CVSS v3 base score is 9.8 out of 10.