Information disclosure in Backdrop
CVE-2026-104476
Backdrop CMS before 1.35.1 contains an information disclosure vulnerability that allows unauthenticated attackers to retrieve configuration export archives left on the server after transfer. Attackers can download compressed archives generated by users with configuration export permission to obtain the full site configuration, including sensitive settings.
Vulnerability class: Information Disclosure
Published .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/backdrop/backdrop/commit/1ae67061d9d487bb6cb3b8611191354052f34749 (patch)
- backdropcms.org/security/backdrop-sa-core-2026-006 (vendor-advisory)
- github.com/backdrop/backdrop (product)
- www.vulncheck.com/advisories/backdrop-cms-before-1.35.1-information-disclosure-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-104476?
- CVE-2026-104476 is a medium-severity vulnerability in Backdrop, classified under Information Disclosure. CVSS score: 5.9/10. Published 2026-10-03.
- How severe is CVE-2026-104476?
- Medium severity. CVSS v3 base score is 5.9 out of 10.