CVE-2026-88015: rclone local symlink Range header DoS

CVE-2026-88015 · Severity: medium · CVSS 5.3 · Published 2026-09-10

rclone is a popular command-line tool for syncing files to cloud storage and serving local directories over HTTP/WebDAV. When configured to expose symlinks as objects (--links flag), a remote attacker can send a single crafted HTTP Range request to crash the request handler, making the service unavailable for that connection. No authentication is required and the attack is fully deterministic.

Technologies: github.com/rclone/rclone (Go), Rclone. Vendors: Go, Rclone.

Quick answers

Is CVE-2026-88015 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-88015 being exploited in the wild.
How severe is CVE-2026-88015?
Medium severity, with a CVSS score of 5.3, published 10 September 2026.
Which products and versions are affected?
github.com/rclone/rclone (Go) <= 1.75.0, SEMVER:introduced=0,fixed=1.75.1; Rclone <= 1.75.0.
Is there a fix for CVE-2026-88015?
Yes. github.com/rclone/rclone (Go): upgrade to 1.75.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-88015 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-88015?
Check whether you run github.com/rclone/rclone (Go) or 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

  • github.com/rclone/rclone (Go): upgrade to 1.75.1 or later
    go get github.com/rclone/rclone@v1.75.1

Technical details

The vulnerability exists in rclone's backend/local module when the `--links` flag is enabled, exposing symlinks as rclone objects. The `Object.Open()` method decodes an incoming HTTP Range header (e.g., `Range: bytes=9223372036854775807-`) without properly validating the offset parameter before passing it to `openTranslatedLink()`. That function then attempts to slice a string with the unchecked offset: `linkdst[offset:]`, causing a runtime panic when offset exceeds the string length. The suffix-range branch (`bytes=-N`) already included bounds-clamping logic from a prior fix, but the ordinary range branch (`bytes=X-`) was never hardened. The fix clamps the offset to the target string's length before slicing. The vulnerability requires the `--links` flag to be active and the attacker must reach the HTTP server (network accessible), but no privileges or user interaction are needed.

Affected products

  • rclone rclone <= 1.75.0

Identifiers

  • CVE-2026-88015
  • GHSA-p6m2-r3w9-mpxw
  • GO-2026-6461

Timeline

  • 2026-09-04: disclosed
  • 2026-09-10: patched: Fixed in rclone v1.75.1

References

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