CVE-2026-104476: Backdrop CMS before 1.35.1 Information Disclosure via Configuration Export Archive

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-03 · updated 2026-10-06
Weakness: CWE-200

Description

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.

Affected products

backdrop: before 1.35.1 — fixed in 1.35.1

How to fix

Upgrade to a fixed version: backdrop 1.35.1. Check the vendor advisory for mitigations.

References

https://backdropcms.org/security/backdrop-sa-core-2026-006
https://github.com/backdrop/backdrop
https://github.com/backdrop/backdrop/commit/1ae67061d9d487bb6cb3b8611191354052f34749
https://www.vulncheck.com/advisories/backdrop-cms-before-1.35.1-information-disclosure-via-configuration-export-archive

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