{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77763","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-08-21T10:30:49.467Z","datePublished":"2026-08-21T11:05:13.650Z","dateUpdated":"2026-08-21T21:44:37.044Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-08-21T11:05:13.650Z"},"datePublic":"2026-08-15T00:00:00.000Z","title":"JuiceFS Local Filestore Backend Joins Object Keys onto the Storage Root Without a Containment Check, Allowing Writes Outside the Configured Directory","descriptions":[{"lang":"en","value":"The filestore backend in pkg/object/file.go, used for file:// stores and as a common juicefs sync destination, derived every operation's target from path(key), which returned either filepath.Join(d.root, key) or filepath.Clean(d.root + key) with no check that the result stayed beneath the root. Put, Get, Head, Delete, Chmod, Chown, Symlink and Readlink all consumed that value directly. Object keys enumerated from a source object store during a sync are not constrained the way local filesystem names are, so a key containing traversal segments causes juicefs to write attacker-supplied content to a path outside the intended local destination, and no error is returned. An operator syncing from a bucket whose contents they do not fully control, such as a shared or public bucket or one an attacker can write to, is therefore exposed to a file write at an attacker-influenced location. The fix changes path() to return an error and rejects any key whose resolved path escapes the root."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","cweId":"CWE-22","type":"CWE"}]}],"affected":[{"vendor":"juicedata","product":"juicefs","defaultStatus":"unaffected","repo":"https://github.com/juicedata/juicefs","collectionURL":"https://proxy.golang.org","packageName":"github.com/juicedata/juicefs","packageURL":"pkg:golang/github.com/juicedata/juicefs","versions":[{"version":"0","lessThanOrEqual":"1.4.1","status":"affected","versionType":"semver"}],"programFiles":["pkg/object/file.go"]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:juicedata:juicefs:*:*:*:*:*:*:*:*","versionEndIncluding":"1.4.1"}]}]}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH"}}],"references":[{"url":"https://github.com/juicedata/juicefs/issues/7401","tags":["issue-tracking"],"name":"GitHub Issue #7401"},{"url":"https://github.com/juicedata/juicefs/commit/0bcd70b3d13088d38127d6fb5750c91be7c4ec16","tags":["patch"],"name":"object/file: reject object keys that escape the filestore root (#7425)"},{"url":"https://github.com/juicedata/juicefs/pull/7425","tags":["issue-tracking"],"name":"GitHub Pull Request #7425"},{"url":"https://github.com/juicedata/juicefs/blob/v1.4.1/pkg/object/file.go","tags":["technical-description"],"name":"filestore path() without a containment check at v1.4.1"},{"url":"https://github.com/juicedata/juicefs","tags":["product"]},{"name":"VulnCheck Advisory: JuiceFS Local Filestore Backend Joins Object Keys onto the Storage Root Without a Containment Check, Allowing Writes Outside the Configured Directory","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/juicefs-local-filestore-backend-joins-object-keys-onto-the-storage-root-without-a-containment-check-allowing-writes-outside-the-configured-directory"}],"credits":[{"lang":"en","value":"George Chen","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-21T21:32:48.194454Z","id":"CVE-2026-77763","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":"2026-08-21T21:44:37.044Z"}}]}}