XSS in Themegrill Zakra

CVE-2026-4804

The Zakra theme for WordPress is vulnerable to Stored Cross-Site Scripting via post meta values in all versions up to, and including, 4.2.0. This is due to the theme registering three post meta fields (zakra_menu_item_color, zakra_menu_item_hover_color, and zakra_menu_item_active_color) with 'show_in_rest' => true and 'auth_callback' => '__return_true', but without any sanitize_callback parameter in the register_post_meta() calls. While the classic editor save path applies sanitize_hex_color() sanitization, the REST API path completely bypasses this protection. The unsanitized meta values are then retrieved via get_post_meta() and concatenated directly into CSS strings that are output through wp_add_inline_style() without any 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 the injected page.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.0% 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-2026-4804: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4804?
CVE-2026-4804 is a medium-severity vulnerability in Themegrill Zakra, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-07-03.
How severe is CVE-2026-4804?
Medium severity. CVSS v3 base score is 6.4 out of 10.