Quick answers
- Is CVE-2026-79781 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-79781 being exploited in the wild.
- How severe is CVE-2026-79781?
- Medium severity, with a CVSS score of 6.5, published 25 August 2026.
- Which products and versions are affected?
- github.com/rclone/rclone (Go) SEMVER:introduced=0,fixed=1.74.4; Rclone before 1.74.4.
- Is there a fix for CVE-2026-79781?
- Yes. github.com/rclone/rclone (Go): upgrade to 1.74.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-79781 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-79781?
- 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 1.74.4 or later
go get github.com/rclone/rclone@v1.74.4
Technical details
The vulnerability is a path traversal / improper path normalization flaw in the S3 backend layer (cmd/serve/s3/backend.go). The root cause is use of Go's path.Join() function, which normalizes ".." segments as filesystem-style path components, on opaque S3 object keys that should be treated literally. An attacker can craft S3 requests with object keys such as "../root-secret.txt" to escape the bucket namespace; when path.Join("bucket", "../root-secret.txt") is evaluated, it resolves to "root-secret.txt" in the serve root directory. The vulnerability affects GET (read), PUT (write), and DELETE operations, and requires only network reachability—no authentication is required when the server is run without --auth-key. The fix is available in rclone version 1.74.4 and later.
Affected products
- rclone rclone before 1.74.4
Identifiers
- CVE-2026-79781
- GHSA-8v25-v8p6-qf7v
- GO-2026-6189
Timeline
- 2026-07-08: disclosed: GitHub Security Advisory GHSA-8v25-v8p6-qf7v published
- 2026-08-25: advisory: CVE-2026-79781 published on NVD
- 2026: patched: Fix available in rclone 1.74.4