CVE-2026-18386

WP BackItUp Community Edition <= 2.1.0 - Authenticated (Administrator+) Path Traversal to Arbitrary File Read via 'backup_file' Parameter

2026-09-09 15:19
Nikola Kojic

Strategic Overview

Status
Unpatched
Affected Plugin
WP BackItUp Community Edition
Affected Version
<= 2.1.0
CVSS
4.9Medium
Weakness type
CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVE
CVE-2026-18386
View all WP BackItUp Community Edition vulnerabilities

At a glance

CVE-2026-18386 is a medium-severity Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in the WP BackItUp Community Edition WordPress plugin, affecting versions <= 2.1.0. It carries a CVSS score of 4.9 (reachable over the network; low attack complexity; high confidentiality impact). Exploitation requires an authenticated account at Administrator level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed September 2026, reported by Nikola Kojic.

Vulnerability Overview

The WP BackItUp Community Edition plugin for WordPress is vulnerable to Directory Traversal in all versions up to, and including, 2.1.0 via the 'backup_file' parameter parameter. This makes it possible for authenticated attackers, with administrator-level access and above, to read the contents of arbitrary files on the server, which can contain sensitive information. The basename() normalization present in the handler only executes when the traversed target path does not exist, providing no protection against reads of existing files.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality.

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

WP BackItUp Community Edition <= 2.1.0 carries this weakness at backup_file, and reaching it takes an account at Administrator level or above. Path traversal happens when user-controlled text is used to build a filesystem path without being constrained to an intended directory, so sequences like ../ walk the resolved path somewhere else.

Depending on the operation, it means reading files outside the intended folder — wp-config.php being the usual target — or writing to and deleting paths the web server can touch. No fixed build of this plugin is recorded for WP BackItUp Community Edition yet, so installs running <= 2.1.0 stay exposed until the vendor ships one.

Remediation

No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.

How does WordSec protect against this?

An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-18386https://www.wordfence.com/threat-intel/vulnerabilities/id/50272c8a-2e23-490d-8865-68ae49228895https://nvd.nist.gov/vuln/detail/CVE-2026-18386

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C