CVE-2019-11253: Kubernetes API Server JSON/YAML parsing vulnerable to resource exhaustion attack

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 25.9% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-10-17 · updated 2026-06-17
Weakness: CWE-20

Description

Improper input validation in the Kubernetes API server in versions v1.0-1.12 and versions prior to v1.13.12, v1.14.8, v1.15.5, and v1.16.2 allows authorized users to send malicious YAML or JSON payloads, causing the API server to consume excessive CPU or memory, potentially crashing and becoming unavailable. Prior to v1.14.0, default RBAC policy authorized anonymous users to submit requests that could trigger this vulnerability. Clusters upgraded from a version prior to v1.14.0 keep the more permissive policy by default for backwards compatibility.

Affected products

Kubernetes: from 1.1.0 through 1.12.10; from 1.13.0 before 1.13.12; from 1.14.0 before 1.14.8; from 1.15.0 before 1.15.5; from 1.16.0 before 1.16.2 — fixed in 1.13.12, 1.14.8, 1.15.5, 1.16.2
Red Hat OpenShift Container Platform 4.18: 3.9, 3.10, 3.11

How to fix

Upgrade to a fixed version: Kubernetes 1.13.12, 1.14.8, 1.15.5, 1.16.2. Check the vendor advisory for mitigations.

References

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