CVE-2026-71310

rclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone Memory

MEDIUM
5.9
CVSS Score
Published: August 5, 2026 at 08:17 PM UTC
Updated: September 9, 2026 at 09:07 PM UTC
1 product affected across 1 vendorRclone

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Severity
MEDIUM5.9
Exploit prediction
EPSS 0.6%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.75.0
Affected range stops below 1.75.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.9MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-400CWE-770

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