CVE-2026-17086 ShortPixel Image Optimizer <= 6.5.5 - Authenticated (Author+) PHP Object Injection via Nested JSON Post Content
Authenticated attackers can inject PHP objects via deserialization, potentially leading to code execution or data access if a POP chain exists.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-17086?
CVE-2026-17086 is a high-severity unsafe deserialization vulnerability in ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF, published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-502
Which versions are affected by CVE-2026-17086?
How do I fix CVE-2026-17086?
No fix has been published for CVE-2026-17086 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-17086 being exploited?
There is no known exploitation of CVE-2026-17086 in the wild and no public exploit code.
Sources
Also known as GHSA-mqfm-qx5g-96vc.