CVE-2026-3339: The Keep Backup Daily plugin for WordPress is vulnerable to Limited Path Traversal in all versions up to, and including, 2.1.1 via the `kbd_open_uploa...

Description

The Keep Backup Daily plugin for WordPress is vulnerable to Limited Path Traversal in all versions up to, and including, 2.1.1 via the `kbd_open_upload_dir` AJAX action. This is due to insufficient validation of the `kbd_path` parameter, which is only sanitized with `sanitize_text_field()` - a function that does not strip path traversal sequences. This makes it possible for authenticated attackers, with Administrator-level access and above, to list the contents of arbitrary directories on the server outside of the intended uploads directory.

Metrics

CVSS 3.1

2.7/10

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.38%

29.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

References

Timeline

Published: Mar 21, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-3339?

The Keep Backup Daily plugin for WordPress is vulnerable to Limited Path Traversal in all versions up to, and including, 2.1.1 via the `kbd_open_upload_dir` AJAX action. This is due to insufficient validation of the `kbd_path` parameter, which is only sanitized with `sanitize_text_field()` - a function that does not strip path traversal sequences. This makes it possible for authenticated attackers, with Administrator-level access and above, to list the contents of arbitrary directories on the server outside of the intended uploads directory.

How severe is CVE-2026-3339?

CVE-2026-3339 has a CVSS score of 2.7/10 (LOW severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3339?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.