# CVE-2026-4335: ShortPixel Image Optimizer <= 6.4.3 - Authenticated (Author+) Stored Cross-Site Scripting via Attachment Title

> Authenticated authors can inject scripts via attachment titles, executing code in admin sessions when opening the image editor popup.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 26 Mar 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-g8cg-xh22-8v5v

## What is CVE-2026-4335?

CVE-2026-4335 is a medium-severity cross-site scripting vulnerability in ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF, published on 26 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

The ShortPixel Image Optimizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the attachment post_title in all versions up to, and including, 6.4.3. This is due to insufficient output escaping in the getEditorPopup() function and its corresponding media-popup.php template. Specifically, the attachment's post_title is retrieved from the database via get_post() in AjaxController.php (line 435) and passed directly to the view template (line 449), where it is rendered into an HTML input element's value attribute without esc_attr() escaping (media-popup.php line 139). Since WordPress allows Authors to set arbitrary attachment titles (including double-quote characters) via the REST API, a malicious author can craft an attachment title that breaks out of the HTML attribute and injects arbitrary JavaScript event handlers. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts that execute whenever a higher-privileged user (such as an administrator) opens the ShortPixel AI editor popup (Background Removal or Image Upscale) for the poisoned attachment.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-4335?


## How do I fix CVE-2026-4335?

No fix has been published for CVE-2026-4335 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4335 being exploited?

There is no known exploitation of CVE-2026-4335 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4335 and fix it if it is affected.

What it is: CVE-2026-4335 is a medium-severity cross-site scripting vulnerability in ShortPixel Image Optimizer – Optimize Images, Convert WebP & AVIF, published on 26 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-4335 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-2026-4335/ (Markdown: https://insights.sbomify.com/CVE-2026-4335/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4335
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4335
- OSV: https://osv.dev/vulnerability/CVE-2026-4335

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-4335/
Summaries are generated and may contain mistakes; the official description above is the record.