CVE-2026-10821

Yoast SEO Premium < 27.6.1 - Author+ Arbitrary .htaccess Directive Injection to RCE

Published Sep 2, 2026 CVSS 3.1 · 6.6 Medium EPSS < 1% KEV · Not listed
Description
The Yoast SEO Premium WordPress plugin before 27.6.1 does not sanitize control characters from redirect origins before writing them to the site's Apache configuration file when the file-based redirect mode is enabled, and the redirect-creation endpoint is reachable by users with only Author-level access. This allows such users to inject arbitrary newline-delimited Apache directives into the root .htaccess file. On Apache servers that honour PHP directives, the injection can be chained with the user's own media upload (a polyglot image carrying a PHP payload) and an auto_prepend_file directive to achieve Remote Code Execution.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
First Time appeared Wordpress-extensions
Wordpress-extensions yoast Seo Premium
Vendors & Products Wordpress-extensions
Wordpress-extensions yoast Seo Premium
Type Values Removed Values Added
Description The Yoast SEO Premium WordPress plugin before 27.6.1 does not sanitize control characters from redirect origins before writing them to the site's Apache configuration file when the file-based redirect mode is enabled, and the redirect-creation endpoint is reachable by users with only Author-level access. This allows such users to inject arbitrary newline-delimited Apache directives into the root .htaccess file. On Apache servers that honour PHP directives, the injection can be chained with the user's own media upload (a polyglot image carrying a PHP payload) and an auto_prepend_file directive to achieve Remote Code Execution.
Title Yoast SEO Premium < 27.6.1 - Author+ Arbitrary .htaccess Directive Injection to RCE
Weaknesses CWE-74
References
Metrics cvssV3_1

{'score': 6.6, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
WPScan
Published
Updated
Sep 2, 2026, 2:57 PM
Reserved
Jun 4, 2026, 7:41 AM
Status
Deferred
Published
Sep 2, 2026, 3:17 PM
Modified
Sep 3, 2026, 5:50 PM