CVE-2026-21728Network attack vector

Unauthenticated service interruption via unlimited query results

Published Apr 24, 2026 · Updated Apr 24, 2026

Uncontrolled resource consumption in Grafana Tempo allows remote attackers to interrupt service by submitting search queries with large limits. The query frontend's SearchSharderConfig sets MaxLimit to zero by default, so attacker-controlled limit values permit unbounded result sets and memory allocations. Reachability requires access to the query API; memory exhaustion interrupts service, while the precise failure mode depends on the deployment strategy.

CVSS severity7.5
High
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Uncontrolled resource consumption in Grafana Tempo allows remote attackers to interrupt service by submitting search queries with large limits. The query frontend's SearchSharderConfig sets MaxLimit to zero by default, so attacker-controlled limit values permit unbounded result sets and memory allocations. Reachability requires access to the query API; memory exhaustion interrupts service, while the precise failure mode depends on the deployment strategy.

The record

CVE
CVE-2026-21728
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
Grafana Labs
Product
Grafana Tempo
Classifications
CWE-400, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=v1.3.0 <v2.11.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Grafana Labs · Grafana Tempoversion=v1.3.0 <v2.11.0

Published CVSS scores

7.5Grafana LabsCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo