# CVE-2026-5821: Image Optimizer <= 1.7.4 - Authenticated (Author+) Arbitrary File Deletion via Post Meta Field Injection

> Authenticated attackers can delete arbitrary server files by injecting paths into post meta, causing data loss or denial of service.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/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:** 2 Jul 2026
- **Updated:** 28 Oct 2026
- **Also known as:** GHSA-rhv9-h5xx-r8m5

## What is CVE-2026-5821?

CVE-2026-5821 is a high-severity path traversal vulnerability in elemntor Image Optimizer – Compress Images and Convert to WebP or AVIF, published on 2 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Image Optimizer plugin for WordPress is vulnerable to arbitrary file deletion in versions up to and including 1.7.4. This is due to insufficient path validation in the Image_Backup::remove() function where backup file paths stored in post meta are used directly in file deletion operations without verifying they are within the uploads directory. The plugin stores backup file paths in the image_optimizer_metadata post meta field and trusts these paths completely when deleting backups on the delete_attachment hook. An authenticated attacker with Author-level access can edit the image_optimizer_metadata post meta on their own attachments via WordPress's Custom Fields interface, injecting arbitrary absolute file paths into the backups array. When the attacker subsequently deletes the attachment, the plugin calls File_System::delete() on each path without validation. This makes it possible for authenticated attackers, with Author-level access and above, to delete arbitrary files on the server within the web server's filesystem permissions, potentially leading to denial of service, data loss, or security degradation.

Weakness: CWE-73 (External Control of File Name or Path)

## Which versions are affected by CVE-2026-5821?


## How do I fix CVE-2026-5821?

No fix has been published for CVE-2026-5821 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5821 being exploited?

There is no known exploitation of CVE-2026-5821 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5821 and fix it if it is affected.

What it is: CVE-2026-5821 is a high-severity path traversal vulnerability in elemntor Image Optimizer – Compress Images and Convert to WebP or AVIF, published on 2 Jul 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-2026-5821 in the wild and no public exploit code.

Affected product: elemntor Image Optimizer – Compress Images and Convert to WebP or 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-2026-5821/ (Markdown: https://insights.sbomify.com/CVE-2026-5821/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5821
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5821
- OSV: https://osv.dev/vulnerability/CVE-2026-5821

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-5821/
Summaries are generated and may contain mistakes; the official description above is the record.