What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-24 · updated 2026-10-26
• Weakness: CWE-400

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 products

• Grafana Tempo: from 1.3.0 before 2.8.4; from 2.9.0 before 2.9.2; from 2.10.0 before 2.10.2 — fixed in 2.8.4, 2.9.2, 2.10.2

How to fix

Upgrade to a fixed version: Grafana Tempo 2.8.4, 2.9.2, 2.10.2. Check the vendor advisory for mitigations.

References

• https://grafana.com/security/security-advisories/cve-2026-21728
• https://access.redhat.com/errata/RHSA-2026:21769
• https://access.redhat.com/errata/RHSA-2026:22347
• https://access.redhat.com/errata/RHSA-2026:22423
• https://access.redhat.com/errata/RHSA-2026:23345
• https://access.redhat.com/errata/RHSA-2026:24503
• https://access.redhat.com/security/cve/CVE-2026-21728
• https://bugzilla.redhat.com/show_bug.cgi?id=2461395
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21728.json

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