Tempo TraceQL query with exemplar hint could result in unbounded memory usage

{
  "id": "4e6c73814f05e6d10f9205bb33230fc26e36e2baa4d574806c321a6130c9c9b4",
  "url": "https://osv.dev/vulnerability/CVE-2026-27878",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Tempo TraceQL query with exemplar hint could result in unbounded memory usage",
    "summary": "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.",
    "evidence": "osv:CVE-2026-27878",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-27878",
      "aliases": [
        "CVE-2026-27878",
        "GHSA-6xff-cpcq-vpw2",
        "GO-2026-6325"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/grafana/tempo",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e85bbc57de52cc9044bc0911de0d1afe5d1fbe07"
                },
                {
                  "fixed": "8ce8017366bc1106b75c20864f200ad84f649515"
                },
                {
                  "introduced": "607c7fb69662262bbb4462da1e2d91067dab6785"
                },
                {
                  "fixed": "f9ce27b87f3f95d1d4533cef143e360be0c4a829"
                },
                {
                  "introduced": "5773eb8b0bdd4439a6c065e54f777e4f77d419a1"
                },
                {
                  "fixed": "9ce71d29b791b6a3ee7397038a85d8afc3a250fd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:grafana:tempo:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.6.0"
                      },
                      {
                        "fixed": "2.8.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:grafana:tempo:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.9.0"
                      },
                      {
                        "fixed": "2.9.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:grafana:tempo:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.10.0"
                      },
                      {
                        "fixed": "2.10.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.10.1",
            "v2.10.0",
            "v2.9.1",
            "v2.9.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27878.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.261657601Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27878.json",
        "https://grafana.com/security/security-advisories/cve-2026-27878",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-27878"
      ],
      "provider_metadata": {
        "cna_assigner": "GRAFANA",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "2.6.1"
                  },
                  {
                    "fixed": "2.8.8"
                  },
                  {
                    "introduced": "2.6.0"
                  },
                  {
                    "fixed": "2.10.2"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27878.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-27878",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 505795,
  "published_at": "2026-06-19T19:02:27.028+00:00"
}