# CVE-2026-3220: Multiple Plugins - Unauthenticated Stored XSS via Minify Library

> Unauthenticated attackers can inject arbitrary HTML attributes via predictable minification hashes, leading to stored XSS in affected WordPress caching plugins.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 18 May 2026
- **Updated:** 18 May 2026
- **Also known as:** GHSA-3jpv-pgxw-p274

## What is CVE-2026-3220?

CVE-2026-3220 is a high-severity cross-site scripting vulnerability in Unknown Autoptimize, published on 18 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The Autoptimize WordPress plugin before 3.1.15, Clearfy Cache  WordPress plugin before 2.4.2, Speed Optimizer  WordPress plugin before 7.7.9 are vulnerable to unauthenticated Stored Cross-Site Scripting (XSS) due to a predictable replacement hash used during the HTML minification process and abusing a regular expression. This allows an attacker to inject arbitrary HTML attributes in the final HTML output by anticipating the placeholder format.

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

## Which versions are affected by CVE-2026-3220?


## How do I fix CVE-2026-3220?

No fix has been published for CVE-2026-3220 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3220 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3220 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3220 and fix it if it is affected.

What it is: CVE-2026-3220 is a high-severity cross-site scripting vulnerability in Unknown Autoptimize, published on 18 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3220 exists.

Affected product: Unknown Autoptimize. 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-2026-3220/ (Markdown: https://insights.sbomify.com/CVE-2026-3220/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3220
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3220
- OSV: https://osv.dev/vulnerability/CVE-2026-3220

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3220/
Summaries are generated and may contain mistakes; the official description above is the record.