{"cve":"CVE-2026-77633","nvd":{"published":"2026-09-22T16:17:55.817","modified":"2026-09-26T00:16:35.823","status":"Deferred","description":"Cloudreve is a self-hosted file management and sharing system. Prior to 4.18.0, PrepareUpload in pkg/filemanager/fs/dbfs/upload.go checks a stale in-memory user storage value through validateUserCapacity and later applies an unconditional storage charge outside the same quota-enforcing transaction. An authenticated user with Files.Write permission can issue concurrent upload-session requests that read the same capacity snapshot, all pass the MaxStorage check, and reserve their declared sizes through CommitWithStorageDiff. The resulting reservations can exceed the account quota and can be materialized as chunked uploads that exhaust host storage and deny uploads to other users. The default local-storage policy and default User group are affected. This issue is fixed in version 4.18.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","score":7.1},"cwes":["CWE-362","CWE-367","CWE-770"],"references":["https://github.com/cloudreve/cloudreve/commit/7329602751c00bb4136fe9ad8b364d0df70773df","https://github.com/cloudreve/cloudreve/releases/tag/4.18.0","https://github.com/cloudreve/cloudreve/security/advisories/GHSA-xj3h-wwxq-gfcj"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-77633","score":0.00368,"percentile":0.30725,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-xj3h-wwxq-gfcj","url":"https://osv.dev/vulnerability/GHSA-xj3h-wwxq-gfcj","summary":"Cloudreve: Storage-quota TOCTOU race allows quota bypass and storage-based denial of service","modified":"2026-10-01T20:55:42.489138466Z","packages":[{"ecosystem":"Go","name":"github.com/cloudreve/Cloudreve/v4","purl":"pkg:golang/github.com/cloudreve/Cloudreve/v4","ranges":["<4.0.0-20260715025621-7329602751c0"],"fixed":["4.0.0-20260715025621-7329602751c0"]}]},{"id":"GO-2026-6578","url":"https://osv.dev/vulnerability/GO-2026-6578","summary":"Cloudreve: Storage-quota TOCTOU race allows quota bypass and storage-based denial of service in github.com/cloudreve/Cloudreve","modified":"2026-10-01T20:45:15.886625594Z","packages":[{"ecosystem":"Go","name":"github.com/cloudreve/Cloudreve","purl":"pkg:golang/github.com/cloudreve/Cloudreve","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/cloudreve/Cloudreve/v3","purl":"pkg:golang/github.com/cloudreve/Cloudreve/v3","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/cloudreve/Cloudreve/v4","purl":"pkg:golang/github.com/cloudreve/Cloudreve/v4","ranges":["<4.0.0-20260715025621-7329602751c0"],"fixed":["4.0.0-20260715025621-7329602751c0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}