# CVE-2026-6427: a3 Lazy Load <= 2.7.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Video Element

> Authenticated contributors can inject malicious scripts via crafted video tags, allowing code execution in administrators' browsers.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 28 May 2026
- **Updated:** 28 May 2026
- **Also known as:** GHSA-xgw3-j63x-rv92

## What is CVE-2026-6427?

CVE-2026-6427 is a medium-severity cross-site scripting vulnerability in a3rev a3 Lazy Load, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The a3 Lazy Load plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 2.7.6 This is due to a regex bug in the _filter_videos() method that breaks HTML attribute quoting when processing crafted <video> elements, combined with unescaped output in the admin/views/form-data.php template. An authenticated attacker with Contributor-level access can insert a crafted <video> tag whose src attribute contains an embedded class=" substring that tricks the plugin's class-replacement regex into consuming an attribute-value closing quote. This shifts the HTML5 parser's quote boundary, promoting attacker-controlled text from inside a quoted attribute value into standalone event-handler attributes (autofocus, onfocus). The injected script executes in the browser of any user (including administrators) who views the post.

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

## Which versions are affected by CVE-2026-6427?


## How do I fix CVE-2026-6427?

No fix has been published for CVE-2026-6427 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6427 being exploited?

There is no known exploitation of CVE-2026-6427 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6427 and fix it if it is affected.

What it is: CVE-2026-6427 is a medium-severity cross-site scripting vulnerability in a3rev a3 Lazy Load, published on 28 May 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-2026-6427 in the wild and no public exploit code.

Affected product: a3rev a3 Lazy Load. 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-2026-6427/ (Markdown: https://insights.sbomify.com/CVE-2026-6427/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6427
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6427
- OSV: https://osv.dev/vulnerability/CVE-2026-6427

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6427/
Summaries are generated and may contain mistakes; the official description above is the record.