CVE-2026-71310: rclone Uncontrolled Resource Consumption

Vulnerability summary

CVE-2026-71310 is a medium (CVSS 5.9) Uncontrolled Resource Consumption vulnerability in rclone. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.2% of scored vulnerabilities.

Timeline

1. 05-08-2026
   PublishedVulnerability first disclosed.
2. 31-08-2026
   Last modifiedVulnerability information updated.

Description

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.0, the shared HTTP CONNECT helper in lib/proxy/http.go parses proxy CONNECT responses with http.ReadResponse over an unrestricted buffered reader, allowing a malicious or compromised configured proxy, or an active on-path actor controlling a plaintext HTTP proxy hop, to send oversized headers that grow memory until the rclone process fails. The affected helper is used by FTP and SFTP proxy connections, and SFTP reaches the parser before SSH server authentication, so target host key validation does not constrain a malicious proxy. This issue is fixed in 1.75.0.

• CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.