# CVE-2026-2300: BJ Lazy Load <= 1.0.9 - Authenticated (Contributor+) Stored Cross-Site Scripting via Custom HTML Block

> Authenticated attackers with Contributor access can inject arbitrary scripts via the Custom HTML Block in the BJ Lazy Load WordPress plugin.

- **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:** 12 May 2026
- **Updated:** 13 May 2026
- **Also known as:** GHSA-xfmv-2x8g-8rjp

## What is CVE-2026-2300?

CVE-2026-2300 is a medium-severity cross-site scripting vulnerability in bjornjohansen BJ Lazy Load, published on 12 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The BJ Lazy Load plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `filter_images()` function in all versions up to, and including, 1.0.9. This is due to the use of regex-based HTML processing (`preg_replace`) that does not properly handle HTML attribute boundaries when replacing `src` attributes, allowing crafted content inside a `class` attribute value to be promoted to real DOM attributes after processing. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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

## Which versions are affected by CVE-2026-2300?


## How do I fix CVE-2026-2300?

No fix has been published for CVE-2026-2300 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-2300 being exploited?

There is no known exploitation of CVE-2026-2300 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2300 and fix it if it is affected.

What it is: CVE-2026-2300 is a medium-severity cross-site scripting vulnerability in bjornjohansen BJ Lazy Load, published on 12 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-2026-2300 in the wild and no public exploit code.

Affected product: bjornjohansen BJ 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-2026-2300/ (Markdown: https://insights.sbomify.com/CVE-2026-2300/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2300
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2300
- OSV: https://osv.dev/vulnerability/CVE-2026-2300

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-2300/
Summaries are generated and may contain mistakes; the official description above is the record.