CVE-2026-10821Public exploitNetwork attack vector

Authenticated code execution via Apache directive injection

Published Sep 2, 2026 · Updated Sep 2, 2026

Configuration injection in Yoast SEO Premium before 27.6.1 allows remote authenticated users to execute code through crafted redirects. The redirect endpoint preserves control characters in an origin and writes newline-delimited attacker input into the root .htaccess file. Author-level edit_posts access, non-default file-based redirects, writable Apache configuration, and PHP directive support are required for code execution.

CVSS severity6.6
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Configuration injection in Yoast SEO Premium before 27.6.1 allows remote authenticated users to execute code through crafted redirects. The redirect endpoint preserves control characters in an origin and writes newline-delimited attacker input into the root .htaccess file. Author-level edit_posts access, non-default file-based redirects, writable Apache configuration, and PHP directive support are required for code execution.

The record

CVE
CVE-2026-10821
Published
Sep 2, 2026
Updated
Sep 2, 2026
Vendor
Yoast
Product
Yoast SEO Premium
Classifications
CWE-74, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <27.6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Yoast · Yoast SEO Premiumversion=0 <27.6.1

Published CVSS scores

6.6WPScan CNACVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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