CVE-2026-122322
Description
A flaw was found in Kyverno. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by exhausting system memory. By supplying specially crafted, highly compressed attestation layers in container registry artifacts, an attacker triggers unbounded decompression within the admission controller. This leads to excessive memory consumption, causing the controller process to crash and disrupting admission control operations.
Statement
This vulnerability is rated as Important because an unauthenticated remote actor capable of publishing artifacts to an image registry can trigger an out-of-memory crash of the admission controller, resulting in a cluster-wide disruption of workload admission. Exploitation requires the cluster to run policy configurations that inspect container image attestations against registries hosting malicious, highly compressed payloads. Standard Red Hat OpenShift deployments do not bundle Kyverno by default and rely on alternative policy frameworks, limiting exposure to environments where this component was specifically deployed.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
--- CME Mitigation Guidance (2026-11-06) ---
Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from https://cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure.
The highest-value action is to enforce size limits when decompressing notary attestation predicate layers in extractStatement to prevent out-of-memory crashes: upgrade to kyverno 1.19.2 (or the corresponding fixed Red Hat builds), which enforce an upper size limit on uncompressed data streams and close the reader, closing all 2 injection vectors (decompression bomb in notary attestation layers, crafted gzip predicate layer in registry referrer artifacts). Until patched, this is a concern on Kubernetes clusters running Kyverno policies configured to verify or inspect container image attestations, so restrict access to push or supply artifacts to registries referenced during workload admission, or suspend policies inspecting attestations from untrusted registries. As a compensating measure, monitor cgroup memory pressure using memory.events and PSI to detect rapid memory exhaustion and imminent container OOM kills. These controls limit blast radius and contain exploitation, but they do not fix the underlying unbounded decompression defect — apply the upstream patch to fully remediate.
Highest-impact CME: CME-1010 cgroup Memory Pressure Monitoring (memory.events / PSI) (medium)
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Amplification; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
System resources, CPU and memory, can be quickly consumed. This can lead to poor system performance or system crash.
Frequently Asked Questions
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