ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF: insecure deserialization
ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF
Insecure deserialization in the ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF component. Threat level: High (CVSS 8.8).
Who is affected
This vulnerability affects: ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF. If you use this component on your site, check the version and update it as soon as possible.
How dangerous
Rating: High, CVSS 8.8 out of 10. It is worth acting before the flaw is exploited.
What this flaw is
Insecure deserialization processes input as ready-made objects. With a faulty implementation, this can run code or alter the application logic.
In practice it often leads to remote code execution, i.e. a site takeover.
Score breakdown (CVSS vector)
What the CVSS 8.8 rating means in practice:
- The attack can be carried out remotely, over the internet.
- Requires an ordinary, low-privileged account.
- Requires no action from the victim.
- At risk: data confidentiality, integrity (data can be altered), site availability.
Weakness class: CWE-502.
How to fix: insecure deserialization
- Update the component to the patched version, this class often leads to code execution.
- Treat the site as potentially compromised: look for unknown files and accounts.
- Rotate secrets and, if there are signs of a break-in, restore from a clean backup.
Prefer not to do this yourself? We will handle the update, check for signs of a break-in and secure the site. Write to us →
Frequently asked questions
Does this vulnerability affect my site?
It affects sites that use ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF. Check whether you have this component installed and which version, the flaw only applies to the vulnerable version range. You can verify it in under a minute with our free vulnerability scanner.
How do I check whether I have the vulnerable version?
In your admin panel (in WordPress: Plugins / Themes) check the installed version of ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF and compare it with the vendor advisory that names the fixed version. If it is lower, or you are not sure, run our scanner, which reads the versions visible in the site code.
How urgently should I react?
This is a Wysoka-severity flaw, so treat it as urgent, high-impact vulnerabilities are often exploited automatically within hours of disclosure. Update as soon as possible.
What if a patch is not available yet?
Until a fix ships, reduce the exposure: temporarily disable the vulnerable component, restrict access to the affected functionality, or add a WAF rule blocking the vulnerable request. Keep a current off-site backup and watch for signs of a break-in.
Is updating alone enough?
If the site has not been attacked yet, updating to the patched version closes the hole. If there are already signs of compromise (unknown files, new admin accounts, redirects), the update does not undo the break-in, you also need to clean the site and rotate passwords and the WordPress salts.
Does this flaw affect your site?
We will run a free audit: we check versions, plugins, and configuration, and tell you plainly whether you are safe.
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