CVE-2026-22056: StorageGRID Denial of Service Vulnerability

CVE-2026-22056 Overview

CVE-2026-22056 is a denial of service vulnerability affecting NetApp StorageGRID (formerly StorageGRID Webscale) versions 11.5 and higher. The flaw exists only in non-standard configurations and specific scenarios. An attacker with some control over the environment can cause a partial denial of service against affected deployments. The weakness is categorized as [CWE-774] Allocation of File Descriptors or Handles Without Limits or Throttling. StorageGRID is NetApp's object storage platform used for large-scale unstructured data workloads including archives, backups, and content repositories.

Critical Impact

Successful exploitation causes only a partial denial of service and requires a non-standard configuration plus low-privileged access, limiting real-world exposure.

Affected Products

• NetApp StorageGRID 11.5 and higher
• NetApp StorageGRID Webscale (legacy naming) 11.5 and higher
• Deployments running non-standard configurations as described in the NetApp advisory

Discovery Timeline

• 2026-08-28 - CVE-2026-22056 published to NVD
• 2026-09-01 - Last updated in NVD database

Technical Details for CVE-2026-22056

Vulnerability Analysis

The vulnerability resides in resource-handling logic within StorageGRID 11.5 and later. NetApp classifies the issue under [CWE-774], which covers allocation of file descriptors or handles without limits or throttling. When triggered, the affected component fails to enforce sufficient bounds on resource consumption. This allows an authenticated actor with limited privileges to exhaust a subset of resources and degrade service availability. The impact is scoped to a partial denial of service rather than full outage. According to the CVSS 4.0 vector, only availability of the vulnerable component is affected, while confidentiality and integrity remain intact. Exploitation requires attack complexity considered high and depends on specific preconditions in the target environment.

Root Cause

The root cause is missing or insufficient throttling of allocated handles or descriptors in a StorageGRID component. When the software processes attacker-influenced input under a non-standard configuration, it can allocate resources faster than they are released. This aligns with the [CWE-774] weakness pattern. NetApp has not published detailed root cause internals beyond the security advisory referenced below.

Attack Vector

The attack vector is network-based. The attacker must already hold low-level privileges within the environment and requires the target to run a non-standard configuration. Attack complexity is high, meaning the attacker must satisfy conditions outside their direct control. No user interaction is required. The vulnerability does not enable code execution, data disclosure, or data modification.

No public exploit code, proof-of-concept, or evidence of exploitation in the wild has been reported. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the NetApp Security Advisory NTAP-20260828-0021 for the authoritative technical description.

Detection Methods for CVE-2026-22056

Indicators of Compromise

• Unexpected spikes in file descriptor or handle counts on StorageGRID nodes
• Repeated service degradation or partial API unavailability tied to a specific client or workload
• Elevated resource utilization on StorageGRID components without a corresponding legitimate traffic increase

Detection Strategies

• Inventory StorageGRID deployments and identify systems running version 11.5 or higher against the configurations described in the NetApp advisory
• Correlate authentication logs with resource-exhaustion events to identify low-privileged accounts triggering abnormal allocation patterns
• Baseline normal descriptor and connection counts per StorageGRID node and alert on sustained deviations

Monitoring Recommendations

• Enable and forward StorageGRID audit logs and system metrics to a centralized SIEM for retention and correlation
• Monitor node-level metrics including open file descriptors, active connections, and thread counts
• Set alerts on service availability probes to detect partial denial of service before user-visible impact

How to Mitigate CVE-2026-22056

Immediate Actions Required

• Review the NetApp Security Advisory NTAP-20260828-0021 for the current fixed release list
• Audit StorageGRID configurations and confirm whether the deployment matches the non-standard scenario described by NetApp
• Restrict network access to StorageGRID management and API endpoints to trusted administrative networks
• Enforce least privilege on StorageGRID accounts so that low-privileged users cannot trigger the vulnerable code path

Patch Information

NetApp tracks remediation status for this vulnerability in advisory NTAP-20260828-0021. Consult the advisory for fixed versions and follow standard NetApp upgrade procedures for StorageGRID. Because the flaw only manifests in non-standard configurations, operators should validate their configuration against NetApp guidance before and after upgrading. See the NetApp Security Advisory NTAP-20260828-0021 for authoritative patch details.

Workarounds

• Revert to a supported standard configuration if the non-standard settings described in the advisory are not required
• Apply network segmentation and rate limiting in front of StorageGRID endpoints to reduce exposure until patched
• Remove or disable access for accounts that do not require interaction with the affected component