# CVE-2020-4040: CSRF issue on preview pages in Bolt CMS

> Unauthorized users can generate content previews in Bolt CMS due to missing CSRF protection, bypassing intended role restrictions.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Jun 2020
- **Updated:** 4 Aug 2024
- **Also known as:** AZL-110318, GHSA-2q66-6cc3-6xm8

## What is CVE-2020-4040?

CVE-2020-4040 is a high-severity vulnerability in bolt, published on 8 Jun 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Bolt CMS before version 3.7.1 lacked CSRF protection in the preview generating endpoint. Previews are intended to be generated by the admins, developers, chief-editors, and editors, who are authorized to create content in the application. But due to lack of proper CSRF protection, unauthorized users could generate a preview. This has been fixed in Bolt 3.7.1

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2020-4040?

2 open source packages ship an affected version, including bolt/bolt. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bolt/bolt` | Packagist | All versions | 3.7.1 |
| `bolt/bolt` | Packagist | All versions | 3.7.1 |

Products: Boltcms Bolt.

## How do I fix CVE-2020-4040?

Upgrade bolt/bolt to 3.7.1 or later.

## Is CVE-2020-4040 being exploited?

There is no known exploitation of CVE-2020-4040 in the wild and no public exploit code.

Public exploit code:

- https://github.com/jpvispo/RCE-Exploit-Bolt-3.7.0-CVE-2020-4040-4041 (github_poc): https://github.com/jpvispo/RCE-Exploit-Bolt-3.7.0-CVE-2020-4040-4041

## Other vulnerabilities in bolt

- [CVE-2022-31321](https://insights.sbomify.com/CVE-2022-31321/): Path traversal in n/a (critical 9.1)
- [CVE-2019-10874](https://insights.sbomify.com/CVE-2019-10874/): Bolt Cross Site Request Forgery (CSRF) (high 8.8)
- [CVE-2019-9185](https://insights.sbomify.com/CVE-2019-9185/): Bolt Unrestricted Upload of File with Dangerous Type (high 8.8)
- [CVE-2025-34086](https://insights.sbomify.com/CVE-2025-34086/): Bolt CMS Authenticated Remote Code Execution via Profile Injection and File Rename (high 7.5)
- [CVE-2021-27367](https://insights.sbomify.com/CVE-2021-27367/): Path traversal in bolt/core (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-4040 and fix it if it is affected.

What it is: CVE-2020-4040 is a high-severity vulnerability in bolt, published on 8 Jun 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-4040 in the wild and no public exploit code.

Affected packages and fixed versions:
- bolt/bolt (Packagist): affected all versions; fixed in 3.7.1
- bolt/bolt (Packagist): affected all versions; fixed in 3.7.1

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-2020-4040/ (Markdown: https://insights.sbomify.com/CVE-2020-4040/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-4040
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-4040
- OSV: https://osv.dev/vulnerability/CVE-2020-4040

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-4040/
Summaries are generated and may contain mistakes; the official description above is the record.