{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19820","assignerOrgId":"4ac701fe-44e9-4bcd-9585-dd6449257611","state":"PUBLISHED","assignerShortName":"Bugcrowd","dateReserved":"2026-08-14T05:28:19.979Z","datePublished":"2026-09-01T00:13:03.935Z","dateUpdated":"2026-09-10T23:32:25.536Z"},"containers":{"cna":{"providerMetadata":{"orgId":"4ac701fe-44e9-4bcd-9585-dd6449257611","shortName":"Bugcrowd","dateUpdated":"2026-09-10T23:32:25.536Z"},"title":"Backblaze Client for Windows Improper Link Resolution Vulnerability","problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-59 Improper Link Resolution Before File Access"}]}],"affected":[{"vendor":"Backblaze","product":"Backblaze Client","platforms":["Windows"],"versions":[{"version":"10.0.0.1029","status":"affected","versionType":"custom"},{"version":"10.0.1.1037","status":"affected","versionType":"custom"},{"version":"10.0.2.1047","status":"affected","versionType":"custom"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"A vulnerability in the Backblaze Client allows a local user to make the system not bootable by creating a link from Backblaze's folder to Windows OS system files during a backup. Successful exploitation requires an administrator-level system change that results in the absence of specific Windows OS security controls. This vulnerability is due to improper link resolution."}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"baseScore":5.8,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:L","version":"4.0"}}],"credits":[{"lang":"en","value":"TrendAI Zero Day Initiative","type":"coordinator"},{"lang":"en","value":"hamdi","type":"finder"}],"references":[{"url":"https://www.backblaze.com/computer-backup/docs/backup-client-release-notes-windows"},{"url":"https://www.backblaze.com/status/update"}]},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-59","lang":"en","description":"CWE-59 Improper Link Resolution Before File Access ('Link Following')"}]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-01T15:13:42.323998Z","id":"CVE-2026-19820","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"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":"2026-09-01T15:14:13.872Z"}}]}}