CVE-2026-27878 Tempo TraceQL query with exemplar hint could result in unbounded memory usage

A TraceQL query in Grafana Tempo with a large exemplars hint value can cause the Tempo instance to allocate an excessive amount of memory, resulting in an out-of-memory crash. This could allow an authenticated user to trigger a denial of service against the Tempo service...

CVE-2026-27878

Grafana Tempo is affected by CVE-2026-27878 due to a TraceQL query that uses a large exemplars hint value, which can cause the Tempo instance to allocate excessive memory and crash (out-of-memory) for an authenticated user, enabling a denial of service. The public documents describe the issue and...