# CVE-2024-40643: Joplin has a parsing error leading to Cross-site Scripting (XSS)

> An attacker can execute arbitrary scripts in Joplin by exploiting a parsing error that mishandles illegal tags within HTML content.

- **Severity:** Critical 9.7 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **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:** 9 Sep 2024
- **Updated:** 9 Sep 2024
- **Also known as:** GHSA-g796-3g6g-jmmc

## What is CVE-2024-40643?

CVE-2024-40643 is a critical cross-site scripting vulnerability in laurent22 joplin, published on 9 Sep 2024. 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

Joplin is a free, open source note taking and to-do application. Joplin fails to take into account that "<" followed by a non letter character will not be considered html. As such it is possible to do an XSS by putting an "illegal" tag within a tag.

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

## Which versions are affected by CVE-2024-40643?

It affects 1 product.


Products: Joplin Project Joplin.

## How do I fix CVE-2024-40643?

No fix has been published for CVE-2024-40643 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-40643 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-40643 exists.

## Other vulnerabilities in laurent22 joplin

- [CVE-2022-23340](https://insights.sbomify.com/CVE-2022-23340/): Joplin Vulnerable to Code Injection (critical 9.8)
- [CVE-2023-45673](https://insights.sbomify.com/CVE-2023-45673/): Arbitrary code execution on click of PDF links in Joplin (high 8.9)
- [CVE-2025-27134](https://insights.sbomify.com/CVE-2025-27134/): Privilege escalation in Joplin server via user patch endpoint (high 8.8)
- [CVE-2023-37898](https://insights.sbomify.com/CVE-2023-37898/): Safe mode Cross-site Scripting (XSS) vulnerability in Joplin (high 8.2)
- [CVE-2023-38506](https://insights.sbomify.com/CVE-2023-38506/): Cross-site Scripting (XSS) when pasting HTML into the rich text editor in Joplin (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-40643 and fix it if it is affected.

What it is: CVE-2024-40643 is a critical cross-site scripting vulnerability in laurent22 joplin, published on 9 Sep 2024. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-40643 exists.

Affected product: laurent22 joplin. 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-2024-40643/ (Markdown: https://insights.sbomify.com/CVE-2024-40643/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-40643
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-40643
- OSV: https://osv.dev/vulnerability/CVE-2024-40643

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-40643/
Summaries are generated and may contain mistakes; the official description above is the record.