CVE-2026-3427CWE-79

Yoast SEO <= 27.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'jsonText' Block Attribute

Medium · published March 22, 2026

CVSS v3.1
6.4
EPSS
0%
Percentile
26.8
In the wild
Unconfirmed
What it is

The Yoast SEO – Advanced SEO with real-time guidance and built-in AI plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the the `jsonText` block attribute in all versions up to, and including, 27.1.1 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.

The record
Technical detail
CVSS v3.1
6.4 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00344 · 26.8th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-03-22T03:26Z
EPSS history
Timeline
  • 22 MAR 03:26Z
    Yoast SEO <= 27.1.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'jsonText' Block Attribute
    cvelistv5