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TI-2026-28410 Aliases CVE-2026-39429GHSA-3j3q-wp9x-585p

kcp's cache server is accessible without authentication or authorization checks

Priority MEDIUM 40CWE-302Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-862.

Summary

kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workloads. Prior to 0.30.3 and 0.29.3, the cache server is directly exposed by the root shard and has no authentication or authorization in place. This allows anyone who can access the root shard to read and write to the cache server. This vulnerability is fixed in 0.30.3 and 0.29.3.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00443 38th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed kcp (kcp-dev): 0.30.3, 0.29.3github.com/kcp-dev/kcp (Go): 0.30.3, 0.29.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
kcp-devkcp0.30.0 to before 0.30.3; before 0.29.30.30.3, 0.29.3Patch availableCNA
—github.com/kcp-dev/kcp (Go)0.30.0 to before 0.30.30.30.3Patch availableGHSA-3j3q-wp9x-585p
—github.com/kcp-dev/kcp (Go)before 0.29.30.29.3Patch availableGHSA-3j3q-wp9x-585p
  • kcp Vendorkcp-dev Affected 0.30.0 to before 0.30.3; before 0.29.3 Fixed in 0.30.3, 0.29.3 Patch available CNA
  • github.com/kcp-dev/kcp (Go) Vendor— Affected 0.30.0 to before 0.30.3 Fixed in 0.30.3 Patch available GHSA-3j3q-wp9x-585p
  • github.com/kcp-dev/kcp (Go) Vendor— Affected before 0.29.3 Fixed in 0.29.3 Patch available GHSA-3j3q-wp9x-585p

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:kcp:kcp:*:*:*:*:*:*:*:*before 0.29.3; 0.30.0 to before 0.30.3VulnerableKcp
  • cpe:2.3:a:kcp:kcp:*:*:*:*:*:*:*:* Versions before 0.29.3; 0.30.0 to before 0.30.3 Vulnerable ·Kcp

Remediation

  • Fix · CNA kcp (kcp-dev) Fixed in 0.30.3, 0.29.3
  • Fix · GHSA-3j3q-wp9x-585p github.com/kcp-dev/kcp (Go) Fixed in 0.30.3 Advisory →
  • Fix · GHSA-3j3q-wp9x-585p github.com/kcp-dev/kcp (Go) Fixed in 0.29.3 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-39429
  2. 2026-10-03 Alias added: GHSA-3j3q-wp9x-585p

References

Exploit 1

Advisory 1

Other 3

  • TI-2026-44160 Authentication bypass by spoofing in kcp-dev kcp CVSS 3.1CRITICAL 9.9
  • TI-2025-21304 kcp allows unauthorized creation and deletion of objects in arbitrary workspaces through APIExport Virtual Workspace CVSS 3.1CRITICAL 9.6

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences