XSS in Fahadmahmood Keep Backup Daily

CVE-2026-3577

The Keep Backup Daily plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the backup title alias (`val` parameter) in the `update_kbd_bkup_alias` AJAX action in all versions up to, and including, 2.1.2. This is due to insufficient input sanitization and output escaping. While `sanitize_text_field()` strips HTML tags on save, it does not encode double quotes. The backup titles are output in HTML attribute contexts without `esc_attr()`. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts via attribute injection that will execute whenever another administrator views the backup list page.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (23.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3577: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3577?
CVE-2026-3577 is a medium-severity vulnerability in Fahadmahmood Keep Backup Daily, classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2026-03-21.
How severe is CVE-2026-3577?
Medium severity. CVSS v3 base score is 4.4 out of 10.