{"api_version":"1","generated_at":"2026-06-14T20:03:24+00:00","cve":"CVE-2026-20256","urls":{"html":"https://cve.report/CVE-2026-20256","api":"https://cve.report/api/cve/CVE-2026-20256.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-20256","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-20256"},"summary":{"title":"Improper Input Validation through Protocol-Relative URL in Classic Dashboards in Splunk Enterprise","description":"In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the 'admin' or 'power' Splunk roles could cause data exfiltration through classic dashboards by redirecting a victim to an external site using a protocol-relative URL in a drill-down link.<br><br>The vulnerability exists because the URL classifier in classic dashboards only recognizes `http://` and `https://` schemes when checking for external URLs. Protocol-relative URLs such as `//attacker.com` bypass this check entirely, and Splunk Web does not show the external-navigation warning dialog to the victim.","state":"PUBLISHED","assigner":"cisco","published_at":"2026-06-10 18:16:41","updated_at":"2026-06-10 18:16:41"},"problem_types":["CWE-20","CWE-20 The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program."],"metrics":[{"version":"3.1","source":"psirt@cisco.com","type":"Primary","score":"5.7","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","baseScore":5.7,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"5.7","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","data":{"baseScore":5.7,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","version":"3.1"}}],"references":[{"url":"https://advisory.splunk.com/advisories/SVD-2026-0606","name":"https://advisory.splunk.com/advisories/SVD-2026-0606","refsource":"psirt@cisco.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-20256","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20256","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Splunk","product":"Splunk Enterprise","version":"affected 10.2 10.2.4 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Enterprise","version":"affected 10.0 10.0.7 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Enterprise","version":"affected 9.4 9.4.12 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Enterprise","version":"affected 9.3 9.3.13 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Cloud Platform","version":"affected 10.3.2512 10.3.2512.13 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Cloud Platform","version":"affected 10.2.2510 10.2.2510.15 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Cloud Platform","version":"affected 10.1.2507 10.1.2507.23 custom","platforms":[]},{"source":"CNA","vendor":"Splunk","product":"Splunk Cloud Platform","version":"affected 9.3.2411 9.3.2411.132 custom","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Tony Tong (tongster)","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"20256","cve":"CVE-2026-20256","epss":"0.000450000","percentile":"0.144710000","score_date":"2026-06-13","updated_at":"2026-06-14 00:08:32"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"Splunk Enterprise","vendor":"Splunk","versions":[{"lessThan":"10.2.4","status":"affected","version":"10.2","versionType":"custom"},{"lessThan":"10.0.7","status":"affected","version":"10.0","versionType":"custom"},{"lessThan":"9.4.12","status":"affected","version":"9.4","versionType":"custom"},{"lessThan":"9.3.13","status":"affected","version":"9.3","versionType":"custom"}]},{"product":"Splunk Cloud Platform","vendor":"Splunk","versions":[{"lessThan":"10.3.2512.13","status":"affected","version":"10.3.2512","versionType":"custom"},{"lessThan":"10.2.2510.15","status":"affected","version":"10.2.2510","versionType":"custom"},{"lessThan":"10.1.2507.23","status":"affected","version":"10.1.2507","versionType":"custom"},{"lessThan":"9.3.2411.132","status":"affected","version":"9.3.2411","versionType":"custom"}]}],"credits":[{"lang":"en","value":"Tony Tong (tongster)"}],"datePublic":"2026-06-10T00:00:00.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the 'admin' or 'power' Splunk roles could cause data exfiltration through classic dashboards by redirecting a victim to an external site using a protocol-relative URL in a drill-down link.<br><br>The vulnerability exists because the URL classifier in classic dashboards only recognizes `http://` and `https://` schemes when checking for external URLs. Protocol-relative URLs such as `//attacker.com` bypass this check entirely, and Splunk Web does not show the external-navigation warning dialog to the victim."}],"value":"In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the 'admin' or 'power' Splunk roles could cause data exfiltration through classic dashboards by redirecting a victim to an external site using a protocol-relative URL in a drill-down link.<br><br>The vulnerability exists because the URL classifier in classic dashboards only recognizes `http://` and `https://` schemes when checking for external URLs. Protocol-relative URLs such as `//attacker.com` bypass this check entirely, and Splunk Web does not show the external-navigation warning dialog to the victim."}],"metrics":[{"cvssV3_1":{"baseScore":5.7,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","description":"The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program.","lang":"en","type":"cwe"}]}],"providerMetadata":{"dateUpdated":"2026-06-10T17:15:55.966Z","orgId":"d1c1063e-7a18-46af-9102-31f8928bc633","shortName":"cisco"},"references":[{"url":"https://advisory.splunk.com/advisories/SVD-2026-0606"}],"source":{"advisory":"SVD-2026-0606"},"title":"Improper Input Validation through Protocol-Relative URL in Classic Dashboards in Splunk Enterprise"}},"cveMetadata":{"assignerOrgId":"d1c1063e-7a18-46af-9102-31f8928bc633","assignerShortName":"cisco","cveId":"CVE-2026-20256","datePublished":"2026-06-10T17:15:55.966Z","dateReserved":"2025-10-08T11:59:15.401Z","dateUpdated":"2026-06-10T17:15:55.966Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-06-10 18:16:41","lastModifiedDate":"2026-06-10 18:16:41","problem_types":["CWE-20","CWE-20 The product does not validate or incorrectly validates input that can affect the control flow or data flow of a program."],"metrics":{"cvssMetricV31":[{"source":"psirt@cisco.com","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N","baseScore":5.7,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":2.1,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"20256","Ordinal":"1","Title":"Improper Input Validation through Protocol-Relative URL in Class","CVE":"CVE-2026-20256","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"20256","Ordinal":"1","NoteData":"In Splunk Enterprise versions below 10.2.4, 10.0.7, 9.4.12, and 9.3.13, and Splunk Cloud Platform versions below 10.3.2512.13, 10.2.2510.15, 10.1.2507.23, and 9.3.2411.132, a low-privileged user that does not hold the 'admin' or 'power' Splunk roles could cause data exfiltration through classic dashboards by redirecting a victim to an external site using a protocol-relative URL in a drill-down link.<br><br>The vulnerability exists because the URL classifier in classic dashboards only recognizes `http://` and `https://` schemes when checking for external URLs. Protocol-relative URLs such as `//attacker.com` bypass this check entirely, and Splunk Web does not show the external-navigation warning dialog to the victim.","Type":"Description","Title":"Improper Input Validation through Protocol-Relative URL in Class"}]}}}