CVE-2026-71310

rclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone Memory

Published Aug 5, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-xhf4-832v-7xcr rclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone Memory
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Rclone
Rclone rclone
Vendors & Products Rclone
Rclone rclone
Type Values Removed Values Added
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.
Title rclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone Memory
Weaknesses CWE-400
CWE-770
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 31, 2026, 2:53 PM
Reserved
Aug 5, 2026, 6:14 PM
Status
Awaiting Analysis
Published
Aug 5, 2026, 9:16 PM
Modified
Sep 9, 2026, 8:50 PM
Severity
Moderate
Public date
Aug 5, 2026, 8:17 PM