Volcano Webhook CVE-2026-44247
MEDIUM
GHSA-8wxp-xxp2-rcgx
Severity by source
AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Adjacent vector (in-cluster only), low privilege required (pod execution), scope change reflects admission control disruption beyond the webhook process, availability-only impact.
Primary rating from GitHub Advisory.
CVSS VectorGitHub Advisory
Lifecycle Timeline
3DescriptionGitHub Advisory
Impact
The Volcano webhook server does not enforce a size limit on incoming HTTP request bodies. Any in-cluster pod that can reach the webhook endpoint may send an arbitrarily large request body, potentially causing the webhook server to be killed by OOM. All Volcano deployments with the webhook server exposed to in-cluster traffic are affected.
Patches
This issue will be fixed in the following versions:
- v1.14.2
- v1.13.3
- v1.12.4
Users running versions below these should upgrade accordingly.
Workarounds
No known workarounds. Upgrade to the patched versions listed above.
AnalysisAI
Uncontrolled resource consumption in the Volcano webhook server allows any in-cluster pod with low-privilege access to exhaust the webhook process memory by streaming an arbitrarily large HTTP request body, resulting in an OOM kill. All Volcano deployments across the v1.12.x, v1.13.x, and v1.14.x release lines are affected until the respective patch versions. No public exploit or active exploitation has been identified; EPSS sits at 0.02% (7th percentile), consistent with low observed exploitation activity, though the availability impact on cluster admission control elevates operational priority for multi-tenant environments.
Technical ContextAI
Volcano (pkg:go/volcano.sh/volcano) is a CNCF incubating Kubernetes-native batch scheduling system written in Go, commonly used for HPC, ML, and data-pipeline workloads. Its webhook server implements Kubernetes admission webhooks over HTTPS. The root cause is CWE-400 (Uncontrolled Resource Consumption): Go's net/http server does not impose a default cap on request body size, so without an explicit call to http.MaxBytesReader (or equivalent middleware) before reading the body, a caller can stream unbounded data. The CVSS vector AV:A reflects that the webhook service is reachable only from within the cluster network, and S:C (scope change) captures the fact that a crash of the admission webhook propagates disruption to all Kubernetes admission control paths Volcano handles, affecting objects beyond the webhook process itself.
RemediationAI
Upgrade Volcano to the patched release corresponding to your current branch: v1.12.4 for 1.12.x deployments, v1.13.3 for 1.13.x, or v1.14.2 for 1.14.x. The vendor confirms no workarounds exist for unpatched versions. Full advisory and release details are available at https://github.com/volcano-sh/volcano/security/advisories/GHSA-8wxp-xxp2-rcgx. Until patching is complete, operators can reduce exposure by tightening Kubernetes NetworkPolicy rules to restrict which pods can reach the Volcano webhook service port (typically TCP/443), limiting access to only the kube-apiserver and explicitly authorized namespaces. This reduces the attack surface but does not eliminate the vulnerability if the kube-apiserver itself is used as a relay, and it may interfere with legitimate admission webhook flows if misconfigured. Ensure the webhook server pod is configured with a memory limit and a restart policy so OOM kills result in automatic recovery, minimizing downtime even if an attack occurs.
Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allVendor StatusVendor
SUSE
Severity: Important| Product | Status |
|---|---|
| SUSE Linux Enterprise Server 16.1 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP5 | Affected |
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | Affected |
| openSUSE Leap 15.5 | Affected |
| openSUSE Leap 15.6 | Affected |
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External POC / Exploit Code
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