{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-22561", "assignerOrgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "state": "PUBLISHED", "assignerShortName": "hackerone", "dateReserved": "2026-01-07T15:39:03.440Z", "datePublished": "2026-03-31T15:30:38.876Z", "dateUpdated": "2026-05-10T13:58:31.956Z"}, "containers": {"cna": {"descriptions": [{"lang": "en", "value": "Uncontrolled search path elements in Anthropic Claude for Windows installer (Claude Setup.exe) versions prior to 1.1.3363 allow local privilege escalation via DLL search-order hijacking. The installer loads DLLs (e.g., profapi.dll) from its own directory after UAC elevation, enabling arbitrary code execution if a malicious DLL is planted alongside the installer."}], "affected": [{"defaultStatus": "unaffected", "vendor": "Anthropic", "product": "Claude Desktop - Windows", "versions": [{"version": "0", "status": "affected", "lessThan": "1.1.3363", "versionType": "semver"}]}], "references": [{"url": "https://trust.anthropic.com/resources?s=1cvig6ldp3zvuj1yffzr11&name=cve-2026-22561-dll-search-order-hijacking-in-claude-for-windows-installer"}], "metrics": [{"cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H", "baseScore": 4.7, "baseSeverity": "MEDIUM"}}], "credits": [{"lang": "en", "value": "Kazuma Matsumoto, a security reseaercher at GMO Cybersecurity by IERAE, Inc", "type": "finder"}], "providerMetadata": {"orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "shortName": "hackerone", "dateUpdated": "2026-03-31T18:13:52.328Z"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-427", "lang": "en", "description": "CWE-427 Uncontrolled Search Path Element"}]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-03-31T16:27:37.909291Z", "id": "CVE-2026-22561", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-10T13:58:31.956Z"}}]}}

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{}

{"affected": [{"configurations": [{"platform": ["windows"], "status": "affected", "versions": {"scheme": "semver", "value": "[1.1.3363,1.1.3363)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "Claude Desktop - Windows", "source": "cna", "vendor": "Anthropic"}, "product": "claude_desktop", "vendor": "anthropic"}], "analysis": {"en": {"generated_at": "2026-04-07T09:56:43.489558+00:00", "value": {"mitigation_remediation": ["Update to Anthropic Claude Desktop version\u202f1.1.3363 or newer, which removes the DLL search\u2011order vulnerability. ", "Before updating, check the installer\u2019s directory for any unexpected or malicious DLLs and remove or rename them. ", "Limit write access to the directory containing the installer to prevent unauthorized DLL placement."], "summary": {"action": "Immediate Patch", "impact": "Local Privilege Escalation"}, "threat_synthesis": {"affected_systems": "Users who have installed Anthropic Claude Desktop for Windows with any installer version earlier than 1.1.3363 are affected. The vulnerability exploits the Windows DLL search\u2011order mechanism, so it applies to any Windows environment capable of running the installer and contains that directory structure.", "description_and_impact": "The installer for Anthropic Claude Desktop for Windows loads DLL files from its own directory after user\u2011account\u2011control elevation. Because the search path is not constrained, a malicious DLL with the same name as a legitimate file \u2013 for example profapi.dll \u2013 can be placed beside the installer and will be loaded during installation. This allows an attacker who can run the installer on the target machine to execute arbitrary code with elevated privileges.", "risk_and_exploitability": "The CVSS score of 4.7 indicates moderate severity. The EPSS score of less than 1\u202f% suggests that exploitation is not common in the wild, and the vulnerability is not listed in the CISA KEV catalog. An attacker must have local access, the ability to run the installer, and write permission to the installer\u2019s directory to place a rogue DLL. Given these prerequisites, the risk is moderate but manageable by applying the vendor\u2011recommended fix."}}}}, "created": "2026-03-31T19:54:08.874007+00:00", "title": "DLL Search\u2011Order Hijacking in Anthropic Claude for Windows Installer", "updated": "2026-04-08T20:00:18.396278+00:00", "vendors": ["anthropic", "anthropic$PRODUCT$claude_desktop"]}