dbcve.org
TempoApplication · Grafana

CVE-2026-21728

HIGH · 7.5 CVSS v3.1 Published 2026-04-24
Fix available
A fix is available. Upgrade to 2.8.4 / 2.9.2 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Tempo (a distributed tracing backend) has a vulnerability where queries with large limits can trigger excessive memory allocations, potentially causing service availability issues due to memory exhaustion.

MitigationSet max_result_limit in the Tempo search configuration (e.g., to 262144/2^18) to cap query result sizes, or implement automatic service restarts to clear memory pressure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TempoApplication
Affected:>= 1.3.0, < 2.8.4>= 2.9.0, < 2.9.2>= 2.10.0, < 2.10.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify if Grafana Tempo is deployed
    Check running processes or installed packages for 'tempo' components, or look for Tempo containers/pods in container orchestration systems
    Affected if Tempo is not present in the environment, the system is not affected
  2. Determine the installed Tempo version
    Run 'tempo --version' or check the version from the container image tag, Helm chart version, or binary used
    Affected if The version falls within any of these ranges: >=1.3.0 and <2.8.4, OR >=2.9.0 and <2.9.2, OR >=2.10.0 and <2.10.2
  3. Verify search query feature is enabled
    Examine the Tempo configuration file (commonly tempo.yaml) for the 'search' or 'querier' section to confirm query processing is enabled
    Affected if Search/querier functionality is disabled, the vulnerability cannot be triggered through queries
  4. Check the max_result_limit configuration value
    Inspect the Tempo configuration file under 'search' or 'querier' settings for the 'max_result_limit' parameter and note its value
    Affected if max_result_limit is unset, set to a very high value, or not configured at all (allowing unbounded query limits)

The environment is affected if Grafana Tempo is running a version in the affected ranges AND the search/querier feature is enabled AND max_result_limit is not configured or is set to an excessively high value.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.8.4 / 2.9.2 / 2.10.2 or later
Fixed in 2.8.42.9.22.10.2
Interim mitigation

Set max_result_limit in the Tempo search configuration (e.g., to 262144/2^18) to cap query result sizes, or implement automatic service restarts to clear memory pressure.

Recommended fix High confidence

Upgrade to Tempo 2.10.2 (or 2.9.2/2.8.4 depending on your major version branch)

  1. 1. Identify your current Tempo version using `tempo -v` or checking your deployment configuration
  2. 2. Determine which version branch you are on (1.x, 2.9.x, or 2.10.x)
  3. 3. For 1.x versions: upgrade to Tempo 2.8.4 or later
  4. 4. For 2.9.x versions: upgrade to Tempo 2.9.2 or later
  5. 5. For 2.10.x versions: upgrade to Tempo 2.10.2 or later
  6. 6. After upgrade, verify the service starts successfully and monitor for normal operation
  7. 7. Alternatively, as a config mitigation, set `max_result_limit: 262144` in the search configuration block of your Tempo config file
Caveat Review the Grafana Tempo release notes for your target version to check for any breaking changes or migration requirements

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tempo Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-21728 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data