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.
Metrics
CVSS 3.1 8.6/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| kanbn | kan | >= 0.5.5, <= 0.6.0 |
References
- https://github.com/kanbn/kan
- https://github.com/kanbn/kan/blob/v0.6.0/.env.example#L25-L27
- https://github.com/kanbn/kan/blob/v0.6.0/apps/web/src/pages/api/download/attatchment.ts#L21-L52
- https://github.com/kanbn/kan/commit/53397d8e81dc1494d94132848c1f0416f1152bd7
- https://github.com/kanbn/kan/pull/590
- https://github.com/kanbn/kan/security/advisories/GHSA-qrx8-9hc6-jvqg
- https://hackmd.io/@leediay/HyIxU63ofg
- https://www.vulncheck.com/advisories/kan-0.5.5-through-0.6.0-unauthenticated-ssrf-via-api-download-attatchment
Timeline
- Published
- Oct 14, 2026
- Last modified
- Oct 16, 2026
- NVD status
- Deferred