# CVE-2026-21728: Tempo query limit results in unbounded memory allocation

> CVE-2026-21728: Tempo query limit results in unbounded memory allocation. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-21728
Last updated: 2026-09-09T13:18:44Z

- Published: 2026-04-24 08:00 UTC · Updated: 2026-09-09 13:18 UTC · Assigner: GRAFANA
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.64%, 50th percentile (scored 2026-10-25)
- CISA KEV: no

## Description

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). Alternatively, automatically restart the service.

## Affected vendors and products

- Grafana: Enterprise Traces (GET)
- Grafana: Tempo
- Red Hat: Logging Subsystem for Red Hat OpenShift
- Red Hat: Multicluster Global Hub
- Red Hat: Multicluster Global Hub 1.3.4
- Red Hat: Multicluster Global Hub 1.4.5
- Red Hat: Multicluster Global Hub 1.6.5
- Red Hat: Multicluster Global Hub 1.7.0
- Red Hat: Red Hat Advanced Cluster Management for Kubernetes 2
- Red Hat: Red Hat Ceph Storage 5
- Red Hat: Red Hat Ceph Storage 6
- Red Hat: Red Hat Ceph Storage 9
- Red Hat: Red Hat Enterprise Linux 10
- Red Hat: Red Hat Enterprise Linux 9
- Red Hat: Red Hat multicluster global hub 1.5.3
- Red Hat: Red Hat OpenShift distributed tracing 3

## Tracked companies

- [Grafana Cloud](https://rewindex.com/company/grafana-cloud.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-21728)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-21728)
- [https://grafana.com/security/security-advisories/cve-2026-21728](https://grafana.com/security/security-advisories/cve-2026-21728)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-21728 · Markdown: https://rewindex.com/cve/CVE-2026-21728.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-21728 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:04:32.878Z