# CVE-2026-15273: Automatic.css 4.0.0 - Unauthenticated Stored Cross-Site Scripting via REQUEST_URI

> Unauthenticated attackers can inject scripts via REQUEST_URI that execute when administrators view the Activity Log settings page.

- **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:** 26 Sep 2026
- **Updated:** 26 Sep 2026
- **Also known as:** GHSA-xhhf-8p83-jrh4

## What is CVE-2026-15273?

CVE-2026-15273 is a medium-severity cross-site scripting vulnerability in Automatic.css, published on 26 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Automatic.css plugin for WordPress is vulnerable to Stored Cross-Site Scripting via REQUEST_URI in all version 4.0.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that will execute whenever an administrator accesses the Activity Log settings page.

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

## Which versions are affected by CVE-2026-15273?


## How do I fix CVE-2026-15273?

No fix has been published for CVE-2026-15273 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15273 being exploited?

There is no known exploitation of CVE-2026-15273 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15273 and fix it if it is affected.

What it is: CVE-2026-15273 is a medium-severity cross-site scripting vulnerability in Automatic.css, published on 26 Sep 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-2026-15273 in the wild and no public exploit code.

Affected product: Automatic.css. 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-2026-15273/ (Markdown: https://insights.sbomify.com/CVE-2026-15273/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15273
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15273
- OSV: https://osv.dev/vulnerability/CVE-2026-15273

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15273/
Summaries are generated and may contain mistakes; the official description above is the record.