Vulnerability details

CVE-2026-110628

kanbn kan

Kan 0.5.5 through 0.6.0 Unauthenticated SSRF via /api/download/attatchment

CVSS 4.0

9.2Critical

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.

CVSS scores

Score	Version	Source	Vector
9.2Critical	4.0	CVEProject cvelistV5 (CNA) (VulnCheck)	`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`
8.6High	3.1	CVEProject cvelistV5 (CNA) (VulnCheck)	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N`

Affected products

Vendor	Product	Versions	Source
kanbn	kan	0.5.5 ≤ v ≤ 0.6.0	CVEProject cvelistV5 (CNA)

References and advisories

https://hackmd.io/@leediay/HyIxU63ofg third-party-advisory
https://github.com/kanbn/kan/pull/590 issue-trackingpatch
https://github.com/kanbn/kan/blob/v0.6.0/apps/web/src/pages/api/download/attatchment.ts#L21-L52 technical-description
https://github.com/kanbn/kan/blob/v0.6.0/.env.example#L25-L27 technical-description
https://github.com/kanbn/kan/security/advisories/GHSA-qrx8-9hc6-jvqg vendor-advisory
https://github.com/kanbn/kan/commit/53397d8e81dc1494d94132848c1f0416f1152bd7 patch
https://github.com/kanbn/kan product
https://www.vulncheck.com/advisories/kan-0.5.5-through-0.6.0-unauthenticated-ssrf-via-api-download-attatchment third-party-advisory

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Details

Published: 2026-10-14
Last updated: 2026-10-16
State: Published
Assigner (CNA): VulnCheck

Exploit prediction (EPSS)

0.42%

Probability of exploitation in 30 days

37%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: Yes
Exploitation: None
Technical impact: Partial

Weaknesses (CWE)

CWE-918
Server-Side Request Forgery (SSRF)