CVE-2026-116189: rclone selfupdate signature verification bypass in SHA256SUMS

CVE-2026-116189 · Severity: high · CVSS 7.5 · Published 2026-10-25

rclone is a file synchronization tool that can automatically update itself. The selfupdate feature validates that downloaded updates are legitimate using cryptographic signatures. However, attackers who compromise the distribution path can prepend a malicious checksum to trick the verification into accepting a forged rclone executable, leading to arbitrary code execution with the privileges of the user running the update.

Technologies: Rclone. Vendors: Rclone.

Quick answers

Is CVE-2026-116189 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-116189 being exploited in the wild.
How severe is CVE-2026-116189?
High severity, with a CVSS score of 7.5, published 25 October 2026.
Which products and versions are affected?
Rclone 1.55.0 before 1.75.2.
Is there a fix for CVE-2026-116189?
Yes: fixed in 1.75.2. Until then: Avoid running selfupdate without explicit verification; use the --check flag to independently verify checksums or GPG signatures before applying updates, or disable automatic updates until patched. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-116189 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-116189?
Check whether you run Rclone at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Fixed in: 1.75.2

Avoid running selfupdate without explicit verification; use the --check flag to independently verify checksums or GPG signatures before applying updates, or disable automatic updates until patched.

Technical details

The vulnerability is a cryptographic verification bypass where rclone validates the signature over the PGP-clearsigned block but searches for the archive hash in the original, partially unsigned response buffer. An attacker controlling the distribution endpoint can prepend an unsigned checksum line matching a malicious archive; the signed block validation succeeds (unsigned bytes are discarded), but findFileHash returns the attacker's unsigned checksum from the prefix. Exploitation requires network-level control of the release distribution path and affects versions 1.55.0 through 1.75.1.

Affected products

  • rclone rclone 1.55.0 before 1.75.2

Timeline

  • 2026-10-09: disclosed
  • 2026-10-25: patched: Version 1.75.2 released

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.