---
id: CVE-2026-17086
title: >-
  The ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF plugin
  for WordPress is vulnerable to PHP Object Injection in all versions up to, and
  including, 6.5.5 via deserialization of untrusted input 
summary: >-
  The ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF plugin
  for WordPress is vulnerable to PHP Object Injection in all versions up to, and
  including, 6.5.5 via deserialization of untrusted input . This makes it
  possible …
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: shortpixel
product: 'ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF'
affected:
  - image_optimizer_optimize_images_convert_webp_avif <= 6.5.5
published: '2026-09-18'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T15:17:06.153'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-17086'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.1/build/shortpixel/replacer2/src/Replacer.php#L259
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.1/build/shortpixel/replacer2/src/Replacer.php#L402
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.1/build/shortpixel/replacer2/src/Replacer.php#L425
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.1/build/shortpixel/replacer2/src/Replacer.php#L429
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.1/build/shortpixel/replacer2/src/Replacer.php#L446
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.1/class/Controller/Optimizer/OptimizeAiController.php#L598
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.4/build/shortpixel/replacer2/src/Replacer.php#L259
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.4/build/shortpixel/replacer2/src/Replacer.php#L402
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.4/build/shortpixel/replacer2/src/Replacer.php#L425
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.4/build/shortpixel/replacer2/src/Replacer.php#L429
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.4/build/shortpixel/replacer2/src/Replacer.php#L446
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/shortpixel-image-optimiser/tags/6.5.4/class/Controller/Optimizer/OptimizeAiController.php#L598
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&old=3688579%40shortpixel-image-optimiser&new=3688579%40shortpixel-image-optimiser
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/89ef2ee1-2bec-459f-9a85-c260cbb129ca?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T14:18:23.587550Z'
epss: 0.0089
epssPercentile: 0.57659
ingestedAt: '2026-09-18T04:35:20.018Z'
---

## Overview

The ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 6.5.5 via deserialization of untrusted input . This makes it possible for authenticated attackers, with author-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.