CVE-2026-21728

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.

What this means for your business

It affects Grafana Tempo. It matters if your company, or a supplier that handles your data, runs it.
An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
FIRST's prediction model gives it a 0.6% chance of attack attempts being seen in the next 30 days, ranking above 48% of all known flaws.

What to do

1Check whether your company or your suppliers run Grafana Tempo, and which version. The affected versions are listed further down this page.
2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS: 7.5 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-400
Assigned by: security@grafana.com

Dates

Published: 2026-04-24
Last modified: 2026-09-09
Sources: NVD

Affected products

Grafana Tempo1.3.0 - 2.8.4, 2.9.0 - 2.9.2, 2.10.0 - 2.10.2

As listed in the NVD configuration data. Not a statement about your estate.