Grafana Tempo Large Limit Memory Allocation DoS
CVE-2026-21728 Published on April 24, 2026

Tempo query limit results in unbounded memory allocation
Tempo queries with large limits can cause large memory allocations which can impact the availability of the service, depending on its deployment strategy. Mitigation can be done by setting max_result_limit in the search config, e.g. to 262144 (2^18).

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-21728 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Types

What is a Resource Exhaustion Vulnerability?

The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

CVE-2026-21728 has been classified to as a Resource Exhaustion vulnerability or weakness.

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-21728

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Red Hat Multicluster Globalhub
 
Red Hat Ceph Storage
 
Red Hat Openshift Distributed Tracing
 
Red Hat Logging
 
Red Hat Acm
 
Red Hat Enterprise Linux (RHEL)
 

Affected Versions

Grafana Tempo: Red Hat Multicluster Global Hub 1.3.4: Red Hat Multicluster Global Hub 1.4.5: Red Hat Multicluster Global Hub 1.5.4: Red Hat Multicluster Global Hub 1.6.2: Red Hat Multicluster Global Hub 1.7.1: Red Hat Ceph Storage 5: Red Hat Ceph Storage 6: Red Hat Ceph Storage 9: Red Hat OpenShift distributed tracing 3: Logging Subsystem for Red Hat OpenShift: Red Hat Multicluster Global Hub: Red Hat Advanced Cluster Management for Kubernetes 2: Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 9:

Exploit Probability

EPSS
0.39%
Percentile
30.43%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.