ShellHub: Cross-tenant IDOR in `GET /api/namespaces/:tenant` via API Key bypasses membership check

published 2026-05-07 6 mo ago modified 2026-06-25 4 mo ago also GHSA-vwx9-7qcf-gg7f , GO-2026-5680 , EUVD-2026-30190

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 23%
public exploits: 0; none known

ShellHub is a centralized SSH gateway. Prior to 0.24.2, GET /api/namespaces/:tenant returns the full namespace object — including the members list (user IDs, e-mails, roles), settings, and device counts — to any caller authenticated by an API Key, for any tenant, regardless of the API Key's own tenant scope. The handler conditionally skips the membership check when the user ID (X-ID) is absent, which is exactly the case for API Key authentication. This vulnerability is fixed in 0.24.2.

Patch / fix

fixed in 2 distros 1

go github.com/shellhub-io/shellhub 0.24.2
shellhub shellhub 0.24.2

govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-14)

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 23% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/shellhub-io/shellhub/security/advisories/GHSA-vwx9-7qcf-gg7f referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/shellhub-io/shellhub	<0.24.2	0.24.2

Affected products

shellhub-io shellhub

Classification

Weakness

CWE-639 Authorization Bypass Through User-Controlled Key

References

github.com /shellhub-io/shellhub/security/advisories/GHSA-vwx9-7qcf-gg7f
exploit, web, vendor-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2026-44426
advisory
github.com /shellhub-io/shellhub
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary