CVE-2026-125409
Passster <= 4.3.21 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'metavalue' Parameter
- Medium 6.4
Description
The Passster – Password Protect Pages and Content plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'metavalue (metakeyinput=passster_id | passster_headline)' parameter in all versions up to, and including, 4.3.21 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. A Contributor can break out of the shortcode attribute context by embedding a ] character in the passster_id or passster_headline meta value to prematurely close the opening shortcode tag, then append a [/passster] closing tag so that the trailing HTML payload is emitted verbatim by do_shortcode() — bypassing the per-attribute escaping present inside render_shortcode() — and the script will also execute in an editor's or administrator's browser when they preview the Contributor's pending post, since filter_the_content() has no edit-permission capability gate.
Key facts
- Published
- 13 Nov 2026
- Last changed
- 13 Nov 2026
- Assigned by
- Wordfence
- EPSS
- 0.287% likely to be exploited in the next 30 days, higher than 21.463% of CVEs (scores for 15 Nov 2026)
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 6.4CVSS 3.1, Mediumfrom the CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
No explicit remediation statement is available on this page yet. Consult the original record and vendor references before choosing a fix.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| wpchill | Passster – Password Protect Pages and Content |
|
Timeline
- 9 Nov 2026 Vendor Notified
- 12 Nov 2026 Disclosed
- 13 Nov 2026 Published
Weakness
Practice this bug class
HackZoneLabs has a hands-on lab on XSS (stored, reflected, DOM) (CWE-79).