# CVE-2023-33969: Stored Cross site scripting in the Task External Link Functionality in Kanboard

> Stored XSS in Kanboard allows attackers to execute arbitrary JavaScript, though default CSP settings mitigate this risk.

- **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:** 5 Jun 2023
- **Updated:** 8 Jan 2025
- **Also known as:** GHSA-8qvf-9847-gpc9

## What is CVE-2023-33969?

CVE-2023-33969 is a medium-severity cross-site scripting vulnerability in kanboard, published on 5 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Kanboard is open source project management software that focuses on the Kanban methodology. A stored Cross site scripting (XSS) allows an attacker to execute arbitrary Javascript and any user who views the task containing the malicious code will be exposed to the XSS attack. Note: The default CSP header configuration blocks this javascript attack. This issue has been addressed in version 1.2.30. Users are advised to upgrade. Users unable to upgrade should ensure that they have a restrictive CSP header config.

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

## Which versions are affected by CVE-2023-33969?

It affects 1 product.


Products: Kanboard Kanboard.

## How do I fix CVE-2023-33969?

No fix has been published for CVE-2023-33969 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-33969 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-33969 exists.

## Other vulnerabilities in kanboard

- [CVE-2026-21881](https://insights.sbomify.com/CVE-2026-21881/): Kanboard is Vulnerable to Reverse Proxy Authentication Bypass (critical 9.1)
- [CVE-2025-55010](https://insights.sbomify.com/CVE-2025-55010/): Kanboard Authenticated Admin Remote Code Execution via Unsafe Deserialization of Events (critical 9.1)
- [CVE-2024-51747](https://insights.sbomify.com/CVE-2024-51747/): Arbitrary File Read and Delete in kanboard (critical 9.1)
- [CVE-2024-51748](https://insights.sbomify.com/CVE-2024-51748/): Remote code execution through language setting in kanboard (critical 9.1)
- [CVE-2017-12850](https://insights.sbomify.com/CVE-2017-12850/): Business logic in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-33969 and fix it if it is affected.

What it is: CVE-2023-33969 is a medium-severity cross-site scripting vulnerability in kanboard, published on 5 Jun 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-33969 exists.

Affected product: kanboard. 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-2023-33969/ (Markdown: https://insights.sbomify.com/CVE-2023-33969/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-33969
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-33969
- OSV: https://osv.dev/vulnerability/CVE-2023-33969

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-33969/
Summaries are generated and may contain mistakes; the official description above is the record.