# CVE-2026-32255: Kan is Vulnerable to Unauthenticated SSRF via Attachment Download Endpoint

> Unauthenticated attackers can exploit an SSRF vulnerability in Kan to access internal services and cloud metadata via the attachment download endpoint.

- **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:** No
- **Published:** 18 Mar 2026
- **Updated:** 19 Mar 2026

## What is CVE-2026-32255?

CVE-2026-32255 is a high-severity server-side request forgery vulnerability in kanbn kan, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kan is an open-source project management tool. In versions 0.5.4 and below, the /api/download/attatchment endpoint has no authentication and no URL validation. The Attachment Download endpoint accepts a user-supplied URL query parameter and passes it directly to fetch() server-side, and returns the full response body. An unauthenticated attacker can use this to make HTTP requests from the server to internal services, cloud metadata endpoints, or private network resources. This issue has been fixed in version 0.5.5. To workaround this issue, block or restrict access to /api/download/attatchment at the reverse proxy level (nginx, Cloudflare, etc.).

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-32255?

It affects 1 product.


Products: Kan Kan.

## How do I fix CVE-2026-32255?

No fix has been published for CVE-2026-32255 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-32255 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32255 exists.

Public exploit code:

- This repository contains a proof of concept (POC) for CVE-2026-32255, a high-severity Server-Side Request Forgery (SSRF) vulnerability in Kan, an open-source project management tool. (github_poc): https://github.com/kOaDT/poc-cve-2026-32255
- Kan <= 0.5.4 - Server-Side Request Forgery (nuclei): http/cves/2026/CVE-2026-32255.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32255 and fix it if it is affected.

What it is: CVE-2026-32255 is a high-severity server-side request forgery vulnerability in kanbn kan, published on 18 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32255 exists.

Affected product: kanbn kan. 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-2026-32255/ (Markdown: https://insights.sbomify.com/CVE-2026-32255/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32255
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32255
- OSV: https://osv.dev/vulnerability/CVE-2026-32255

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32255/
Summaries are generated and may contain mistakes; the official description above is the record.