What is CVE-2026-21729?

CVE-2026-21729 is a high-severity vulnerability in Grafana Loki, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-16.

How severe is CVE-2026-21729?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Grafana Loki

CVE-2026-21729

Loki queries with large limits can cause large memory allocations which can impact the availability of the service, depending on its deployment strategy.

EPSS: 0.005 (38.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Grafana Loki — versions v3.0.0

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

security@grafana.com (vendor-advisory)

Frequently asked questions

What is CVE-2026-21729?: CVE-2026-21729 is a high-severity vulnerability in Grafana Loki, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-16.
How severe is CVE-2026-21729?: High severity. CVSS v3 base score is 7.5 out of 10.