Auth bypass in Alchemycms Alchemy Cms
CVE-2026-86777
AlchemyCMS versions before 7.4.16 and 8.x before 8.3.6 fail to authorize access to the GET /api/nodes endpoint, allowing unauthenticated attackers to retrieve all navigation nodes. Attackers can access the endpoint without authentication to disclose restricted page names, URL paths, and internal URLs from all sites and languages.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/AlchemyCMS/alchemy_cms (product)
- github.com/AlchemyCMS/alchemy_cms/blob/v8.3.5/app/controllers/alchemy/api/nodes… (technical-description)
- github.com/AlchemyCMS/alchemy_cms/commit/5e2cd16a806c9d2df3eb6e3c889402487e0085… (patch)
- github.com/AlchemyCMS/alchemy_cms/commit/9bdb98496d6f17277ed05dd1abc3188f880aa5… (patch)
- github.com/AlchemyCMS/alchemy_cms/releases/tag/v7.4.16 (release-notes)
- github.com/AlchemyCMS/alchemy_cms/releases/tag/v8.3.6 (release-notes)
- github.com/AlchemyCMS/alchemy_cms/security/advisories/GHSA-wppq-8h64-w78r (vendor-advisory)
- www.vulncheck.com/advisories/alchemycms-before-7.4.16-and-8-x-before-8.3.6-miss… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-86777?
- CVE-2026-86777 is a medium-severity vulnerability in Alchemycms Alchemy Cms, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-09-09.
- How severe is CVE-2026-86777?
- Medium severity. CVSS v3 base score is 5.3 out of 10.