CVE-2026-64638

WordPress Core <= 7.0.2 - Unauthenticated Reflected Cross-Site Scripting via log Parameter

2026-08-08 00:00
pwn.ai Team

Strategic Overview

Status
Patched in 4.7.34
Affected Core
WordPress 7.0
Affected Version
4.7.0 – 7.0.2 · 24 branches
CVSS
6.1Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-64638
View all WordPress 7.0 vulnerabilities

At a glance

CVE-2026-64638 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the WordPress 7.0 WordPress release line, affecting 4.7.0 – 7.0.2 · 24 branches. It carries a CVSS score of 6.1 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 4.7.34; sites on affected versions should update now. Disclosed August 2026, reported by pwn.ai Team.

Vulnerability Overview

WordPress Core is vulnerable to Reflected Cross-Site Scripting via the 'log' parameter in all versions up to, and including, 7.0.2 due to insufficient input sanitization and output escaping of the authentication error messages rendered on the login screen. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as visiting a specially crafted, attacker-controlled page that submits a request to the vulnerable site.

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.

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

WordPress 7.0 4.7.0 – 7.0.2 · 24 branches carries this weakness at log, 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 7.0 the fix is 4.7.34: builds 4.7.0 – 7.0.2 · 24 branches are affected, anything from 4.7.34 onward is not.

Remediation

Update to one of the following versions, or a newer patched version: 4.7.34, 4.8.29, 4.9.30, 5.0.26, 5.1.23, 5.2.25, 5.3.22, 5.4.20, 5.5.19, 5.6.18, 5.7.16, 5.8.14, 5.9.14, 6.0.13, 6.1.11, 6.2.10, 6.3.9, 6.4.9, 6.5.9, 6.6.6, 6.7.6, 6.8.7, 6.9.6, 7.0.3

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 4.7.34 is the step that ends it.

  • Firewall
  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-64638https://www.wordfence.com/threat-intel/vulnerabilities/id/278da117-fe04-45d6-86d4-e71fe6536032https://nvd.nist.gov/vuln/detail/CVE-2026-64638

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C