CVE-2026-2430

Autoptimize <= 3.1.14 - Authenticated (Contributor+) Stored Cross-Site Scripting via Lazy-loaded Image Attributes

2026-03-20 00:00
stealthcopter

Strategic Overview

Status
Patched in 3.1.15
Affected Plugin
Autoptimize
Affected Version
<= 3.1.14
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-2430
View all Autoptimize vulnerabilities

At a glance

CVE-2026-2430 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Autoptimize WordPress plugin, affecting versions <= 3.1.14. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 3.1.15; sites on affected versions should update now. Disclosed March 2026, reported by stealthcopter.

Vulnerability Overview

The Autoptimize plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the lazy-loading image processing in all versions up to, and including, 3.1.14. This is due to the use of an overly permissive regular expression in the `add_lazyload` function that replaces all occurrences of `\ssrc=` in image tags without limiting to the actual attribute. 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 by crafting an image tag where the `src` URL contains a space followed by `src=`, causing the regex to break the HTML structure and promote text inside attribute values into executable HTML attributes.

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 interaction from a victim user.

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

Reaching this weakness in Autoptimize <= 3.1.14 takes an account at Contributor level or above. 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 Autoptimize the fix is 3.1.15: builds <= 3.1.14 are affected, anything from 3.1.15 onward is not.

Remediation

Update to version 3.1.15, or a newer patched version

How does WordSec protect against this?

An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Autoptimize 3.1.15 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-2430https://www.wordfence.com/threat-intel/vulnerabilities/id/ddc5c4d7-09dc-45bf-a3c7-5a0757e3110ahttps://nvd.nist.gov/vuln/detail/CVE-2026-2430

Related records

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