CVE-2026-71310 rclone: Unbounded HTTP CONNECT Response Headers Can Exhaust rclone Memory
A malicious proxy can cause rclone to crash by sending oversized HTTP CONNECT response headers, requiring a proxy configuration to exploit.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-71310?
CVE-2026-71310 is a medium-severity denial of service vulnerability in rclone, published on 5 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-71310?
4 open source packages ship an affected version, including github.com/rclone/rclone and rclone.
| Package | Affected | Fixed in |
|---|---|---|
github.com/rclone/rclone Go | All versions | 1.75.0 |
github.com/rclone/rclone Go | All versions | 1.75.0 |
github.com/rclone/rclone Go | All versions | 1.75.0 |
rclone Bitnami | All versions | 1.75.0 |
How do I fix CVE-2026-71310?
Upgrade github.com/rclone/rclone to 1.75.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-71310 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-71310 exists.
Sources
Also known as BIT-rclone-2026-71310, DEBIAN-CVE-2026-71310, GHSA-xhf4-832v-7xcr, GO-2026-6199, MINI-3r7p-w9cf-wmmc, MINI-464m-jqhj-hjgc and 7 more.