# CVE-2026-100506: WordPress WP Spell Check plugin <= 12.1 - PHP Object Injection vulnerability

> An attacker can exploit PHP object injection in the WP Spell Check plugin to potentially execute arbitrary code on the WordPress site.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 6 Oct 2026
- **Also known as:** GHSA-29vv-gx7g-vm7g

## What is CVE-2026-100506?

CVE-2026-100506 is a high-severity unsafe deserialization vulnerability in WP Spell Check, published on 5 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Deserialization of Untrusted Data vulnerability in WP Spell Check WP Spell Check wp-spell-check allows Object Injection.This issue affects WP Spell Check: from n/a through 12.1.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-100506?


## How do I fix CVE-2026-100506?

No fix has been published for CVE-2026-100506 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100506 being exploited?

There is no known exploitation of CVE-2026-100506 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100506 and fix it if it is affected.

What it is: CVE-2026-100506 is a high-severity unsafe deserialization vulnerability in WP Spell Check, published on 5 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-100506 in the wild and no public exploit code.

Affected product: WP Spell Check. 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-2026-100506/ (Markdown: https://insights.sbomify.com/CVE-2026-100506/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100506
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100506
- OSV: https://osv.dev/vulnerability/CVE-2026-100506

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-100506/
Summaries are generated and may contain mistakes; the official description above is the record.