Vulnerability · Published Aug 25, 2026 · Assigned by VulnCheck
CVE-2026-79775rclone Archive Backend SquashFS Parser Denial of Service
Medium 6.5
In plain English
A medium-severity security flaw in rclone from rclone. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).
Official description
rclone versions >= v1.72.0 and <= v1.74.4 (fixed in v1.75.0) contain multiple denial-of-service vulnerabilities in the archive backend's SquashFS parser, which relies on the github.com/diskfs/go-diskfs dependency. The parser fails to validate attacker-controlled superblock and metadata values before use. An attacker who can place or modify a SquashFS image in storage exposed through an rclone :archive: remote can craft a malicious image that triggers an integer division-by-zero panic (zero block size), an out-of-bounds slice panic (out-of-range inode metadata offset), or a non-progress CPU loop (truncated metadata stream). Variants 1 and 2 terminate the rclone process and, via 'rclone serve sftp', can crash the entire SFTP server; variant 3 causes sustained CPU consumption. Parsing is lazy, so a victim or remote client must address or descend into the malicious archive object to trigger it.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | rclone | no fix listed | DEBIAN-CVE-2026-79775 |
| Debian:13 | rclone | no fix listed | DEBIAN-CVE-2026-79775 |
| Ubuntu:26.10 | rclone | no fix listed | UBUNTU-CVE-2026-79775 |
Affected products (as reported)
Weakness: CWE-129 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
References
- GitHub Security Advisory (GHSA-6jcg-q3wp-x2f4) vendor-advisory
- VulnCheck Advisory: rclone Archive Backend SquashFS Parser Denial of Service third-party-advisory