# CVE-2026-110628: Kan 0.5.5 through 0.6.0 Unauthenticated SSRF via /api/download/attatchment

> Unauthenticated attackers can exploit SSRF in Kan to access internal services and cloud metadata when S3_ENDPOINT is unset.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** GHSA-8p5c-vr7c-5g49

## What is CVE-2026-110628?

CVE-2026-110628 is a critical server-side request forgery vulnerability in kanbn kan, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kan 0.5.5 through 0.6.0 contains an unauthenticated server-side request forgery vulnerability in the /api/download/attatchment route due to an incomplete fix for CVE-2026-32255. When S3_ENDPOINT is unset, attackers can pass arbitrary url query parameters to fetch() to read internal services, localhost ports, and cloud instance metadata.

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

## Which versions are affected by CVE-2026-110628?


## How do I fix CVE-2026-110628?

No fix has been published for CVE-2026-110628 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-110628 being exploited?

There is no known exploitation of CVE-2026-110628 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-110628 and fix it if it is affected.

What it is: CVE-2026-110628 is a critical server-side request forgery vulnerability in kanbn kan, published on 14 Oct 2026. 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-2026-110628 in the wild and no public exploit code.

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-2026-110628/ (Markdown: https://insights.sbomify.com/CVE-2026-110628/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-110628
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110628
- OSV: https://osv.dev/vulnerability/CVE-2026-110628

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-110628/
Summaries are generated and may contain mistakes; the official description above is the record.