CVE-2019-11254 — yaml.v2
MEDIUMCVE-2019-11254 is a medium-severity (CVSS 6.5) CWE-1050 vulnerability in gopkg.in/yaml.v2. A fix is available for gopkg.in/yaml.v2 — see the affected versions and patch details below.
Excessive Platform Resource Consumption within a Loop in Kubernetes
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2019-11254 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
gopkg.in/yaml.v2🐹github.com/go-yaml/yamlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
The Kubernetes API Server component in versions 1.1-1.14, and versions prior to 1.15.10, 1.16.7 and 1.17.3 allows an authorized user who sends malicious YAML payloads to cause the kube-apiserver to consume excessive CPU cycles while parsing YAML.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | gopkg.in/yaml.v2 | all versions | 2.2.8go get gopkg.in/yaml.v2@v2.2.8 |
| 🐹Go | github.com/go-yaml/yaml | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gopkg.in/yaml.v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gopkg.in/yaml.v2 to 2.2.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-11254 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2019-11254 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2019-11254. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
The upstream Kubernetes fix for this vulnerability is to update the version of the Go dependency, gopkg.in/yaml.v2. This issue affects OpenShift Container Platform components that use versions before 2.2.8 of gopkg.in/yaml.v2 and accept YAML payloads.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift Container Platform 3.11 | atomic-openshift-0:3.11.232-1.git.0.a5bc32f.el7 | RHSA-2020:2479 |
| Red Hat OpenShift Container Platform 4.3 | openshift4/ose-openshift-apiserver-rhel7:v4.3.9-202003230345 | RHSA-2020:0933 |
| Red Hat OpenShift Container Platform 4.5 | openshift4/ose-hyperkube:v4.5.0-202007100518.p0 | RHSA-2020:2412 |
| Red Hat OpenShift Container Platform 4.5 | openshift-0:4.5.0-202007012112.p0.git.0.582d7fc.el7 | RHSA-2020:2413 |
Frequently Asked Questions
Is CVE-2019-11254 in your dependencies?
O3 Security finds CVE-2019-11254 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.