CVE-2026-39429: kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workload

This week

HIGH 8.2REMOTEWATCHLISTUPGRADE

CVE-2026-39429 is a high-severity flaw (CVSS 8.2) affecting kcp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.2 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 62%)
CISA exploited list	No
Weakness	CWE-302, CWE-862
Published	2026-04-08
Last modified	2026-07-24

Publisher (CNA): GitHub, Inc. · Vendor: kcp

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-08 21:16 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

kcp kcp UPGRADE

Affected: < 0.29.3 · >= 0.30.0 and < 0.30.3

Fixed in: 0.29.3, 0.30.3

Safe to downgrade to: a release before 0.30.0

1. Check installed version

apt-cache policy kcp || rpm -q kcp || kcp --version

2. UPGRADE to 0.29.3 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kcp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kcp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.30.0 (Debian / Ubuntu)

apt-cache madison kcp sudo apt install kcp=<VERSION_BEFORE_0.30.0> sudo apt-mark hold kcp

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list kcp sudo dnf downgrade kcp-<VERSION_BEFORE_0.30.0> sudo dnf versionlock add kcp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39429?

kcp: upgrade to 0.29.3, 0.30.3. Exact commands for each OS are on this page.

Is CVE-2026-39429 being exploited?

CVE-2026-39429 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39429 affect?

CVE-2026-39429 affects kcp. Severity is high (CVSS 8.2). 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 i

How urgent is CVE-2026-39429?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Kubernetes vulnerabilities

References

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