kubectl EUVD-2026-88223

Exploitation requires ALL of: (1) the kubectl client running on Windows specifically - Linux and macOS clients are explicitly not affected; (2) the victim actively invoking kubectl cp to copy files FROM a container (victim interaction is mandatory); (3) the source container being attacker-controlled or untrusted, containing a malicious tar binary that emits traversal path entries; and (4) affected kubectl versions 1.34.0-1.34.11, 1.35.0-1.35.8, or 1.36.0-1.36.4. Impact is LIMITED to paths writable by the local user account running kubectl. Documented mitigations without upgrading: only copy from trusted containers, or avoid kubectl cp from untrusted containers on Windows.

The vendor (Kubernetes Security Response Committee) rated this Medium at CVSS 6.5. No CVSS vector string was published in the provided data, and the linked FIRST article is only the generic calculator page (CVSS/CWE = N/A), so the exact metric breakdown is not confirmed - the 6.5 magnitude and Medium rating are the only hard severity signals. No EPSS score, no CISA KEV listing, and no public proof-of-concept were provided, so the real-world urgency signals are all absent or negative. This is a client-side, victim-triggered path-traversal (CWE-22 class) file-write that only fires when a Windows kubectl user runs kubectl cp FROM an attacker-controlled container - a narrow, opt-in exploitation path rather than a remotely-reachable server flaw. Net assessment: genuinely a real bug worth patching, but low real-world urgency - it is not a mass-exploitable, unauthenticated server vulnerability, and impact is capped at the local user's own file permissions. Treat as routine patch-cycle priority, escalating only for operators who routinely kubectl cp from untrusted/third-party container images on Windows workstations.

An attacker publishes or compromises a container image, planting a malicious tar binary that emits archive entries with traversal paths. A victim running kubectl on Windows executes kubectl cp <pod>:/path ./local to pull files from that container, and the crafted entries cause files to be written outside the intended destination anywhere the local Windows user can write. No public exploit code was identified at time of analysis, though the technique (tar path traversal in kubectl cp) is well understood from prior kubectl cp CVEs.