# CVE-2026-72574: picocms Pico - Host Header Injection Enables Script Source Hijacking

> Unauthenticated attackers can hijack script sources via Host header injection in Pico CMS, potentially leading to code execution.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **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:** 10 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-563g-2g6p-xmpf

## What is CVE-2026-72574?

CVE-2026-72574 is a medium-severity vulnerability in picocms Pico, published on 10 Aug 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

A host header injection vulnerability in picocms/Pico through 2.1.4 allows an unauthenticated remote attacker to control the origin of JavaScript and CSS assets loaded by the default theme. When base_url is unset (the default), Pico::getBaseUrl in lib/Pico.php builds the base URL from unvalidated Host, X-Forwarded-Host, X-Forwarded-Proto, and X-Forwarded-Port request headers.

Weakness: CWE-644 (Improper Neutralization of HTTP Headers for Scripting Syntax)

## Which versions are affected by CVE-2026-72574?


## How do I fix CVE-2026-72574?

No fix has been published for CVE-2026-72574 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-72574 being exploited?

There is no known exploitation of CVE-2026-72574 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72574 and fix it if it is affected.

What it is: CVE-2026-72574 is a medium-severity vulnerability in picocms Pico, published on 10 Aug 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: There is no known exploitation of CVE-2026-72574 in the wild and no public exploit code.

Affected product: picocms Pico. 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-2026-72574/ (Markdown: https://insights.sbomify.com/CVE-2026-72574/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72574
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72574
- OSV: https://osv.dev/vulnerability/CVE-2026-72574

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72574/
Summaries are generated and may contain mistakes; the official description above is the record.