Keep Backup Daily <= 2.1.2 - Authenticated (Admin+) Stored Cross-Site Scripting via Backup Title
Strategic Overview
- Status
- Patched in 2.1.3
- Affected Plugin
- Keep Backup Daily
- Affected Version
<= 2.1.2- CVSS
- 4.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2026-3577
At a glance
CVE-2026-3577 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Keep Backup Daily WordPress plugin, affecting versions <= 2.1.2. It carries a CVSS score of 4.4 (reachable over the network). Exploitation requires an authenticated account at Admin level or above. The issue is fixed in version 2.1.3; sites on affected versions should update now. Disclosed March 2026, reported by san6051.
Vulnerability Overview
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.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Keep Backup Daily <= 2.1.2 carries this weakness at sanitize_text_field(), and reaching it takes an account at Admin level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Keep Backup Daily the fix is 2.1.3: builds <= 2.1.2 are affected, anything from 2.1.3 onward is not.
Remediation
Update to version 2.1.3, or a newer patched version
How does WordSec protect against this?
An attacker needs Admin 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. None of that substitutes for the fix: Keep Backup Daily 2.1.3 closes this, and updating the plugin is the step that ends it.
- Firewall
- Alerts
External References
Related records
Same weakness class
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