# 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.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-mqfm-qx5g-96vc

## 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 (Deserialization of Untrusted Data)

## 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.

## Is CVE-2026-17086 being exploited?

There is no known exploitation of CVE-2026-17086 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-17086 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-17086 in the wild and no public exploit code.

Affected product: ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-17086/ (Markdown: https://insights.sbomify.com/CVE-2026-17086/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-17086
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-17086
- OSV: https://osv.dev/vulnerability/CVE-2026-17086

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-17086/
Summaries are generated and may contain mistakes; the official description above is the record.