WordPress Core <= 7.1 - Unauthenticated Stored Cross-Site Scripting via wpautop() Blockquote Handling

2026-09-17 00:00
Rafie Muhammad

Strategic Overview

Status
Patched in 6.6.8
Affected Core
WordPress 7.1
Affected Version
6.6.7 – 7.1 · 6 branches
CVSS
7.2High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE pending
View all WordPress 7.1 vulnerabilities

At a glance

This record tracks a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WordPress 7.1 WordPress release line, affecting 6.6.7 – 7.1 · 6 branches. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 6.6.8; sites on affected versions should update now. Disclosed September 2026, reported by Rafie Muhammad.

Vulnerability Overview

WordPress Core is vulnerable to Stored Cross-Site Scripting via the wpautop() function in various versions up to, and including, 7.1 due to a paragraph-unwrapping regular expression ('<p><blockquote([^>]*)>') that mishandles a blockquote whose attribute region contains a '>'. Combined with wpautop's blank-line paragraph splitting, a newline placed inside a blockquote cite value causes a paragraph tag to be relocated into the tag. This makes it possible for unauthenticated attackers to inject web scripts via comment content, though the comment may be subject to moderation approval before it is stored and rendered.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

WordPress 7.1 6.6.7 – 7.1 · 6 branches carries this weakness at wpautop(), and reaching it takes no account at all. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For WordPress 7.1 the fix is 6.6.8: builds 6.6.7 – 7.1 · 6 branches are affected, anything from 6.6.8 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 6.6.8, 6.7.8, 6.8.9, 6.9.8, 7.0.5, 7.1.1

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 6.6.8 is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/1984abee-a74c-48d7-874f-c4421243e5e5

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