CVE-2026-79913
Cloudreve: SSRF guard bypass: checkIP does not decode IPv6-transition wrappers (NAT64, IPv4-compatible, 6to4) reaching internal and cloud-metadata addresses
Cloudreve is a self-hosted file management and sharing system. Prior to 4.18.0, the ValidateExternalURL server-side request forgery guard in pkg/request/ssrf.go passes resolved addresses to checkIP without decoding NAT64, IPv4-compatible, and 6to4 IPv4-in-IPv6 transition forms. An authenticated user with remote-download access can provide SrcUri through RemoteDownloadTask.createDownloadTask so a wrapper embedding a loopback, private, link-local, or cloud metadata IPv4 address is classified as public and fetched, exposing internal service responses and cloud instance credentials. IPv4-mapped IPv6 addresses remain blocked because Go converts that form with net.IP.To4. This issue is fixed in version 4.18.0.
- Affected
- cloudreve
- CVSS v3.1 GITHUB
- 6.5 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N - EPSS
- 0.40% chance of exploitation in the next 30 days, 33rd percentile
- Published
- 2026-09-22