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Fencer Vulns
medium 6.5

CVE-2026-79775 json

rclone Archive Backend SquashFS Parser Denial of Service

published 2026-08-25 2 mo ago modified 2026-09-25 44 d ago also BIT-rclone-2026-79775 , EUVD-2026-65533 , GHSA-6jcg-q3wp-x2f4

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

Summary

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.

Patch / fix

  • bitnami rclone 1.75.0
  • rclone rclone 1.75.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-79775 updated cvss 6.5

github.com/diskfs/go-diskfs: rclone: Denial of Service via malicious SquashFS image parsing

  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 assisted/agent-preinstall-image-builder-rhel9
    affected: no fix planned “Out of support scope”
  • Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9
    affected: no fix available “Fix deferred”
  • Red Hat Exploit Intelligence exploit-intelligence/agent-client-rhel9, exploit-intelligence-tech-preview/agent-client-rhel9
    affected: no fix planned “Out of support scope”
  • Red Hat Multicluster Engine for Kubernetes multicluster-engine/assisted-service-8-rhel8, multicluster-engine/assisted-service-9-rhel9, multicluster-engine/image-based-install-rhel9, multicluster-engine/assisted-image-service-rhel8, multicluster-engine/assisted-image-service-rhel9
    affected: no fix available, no fix planned “Out of support scope”
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/volsync-rhel9 Red Hat OpenShift Container Platform 4 kata-containers, openshift4/ose-installer, openshift4/ose-installer-rhel9, openshift4/ose-installer-artifacts, openshift4/ose-installer-altinfra-rhel8, openshift4/ose-installer-altinfra-rhel9, +9 more Red Hat OpenShift Container Platform 5 kata-containers, openshift5/ose-installer-rhel9, openshift5/ose-baremetal-installer-rhel9, openshift5/ose-installer-artifacts-rhel9, openshift5/lifecycle-agent-rhel9-operator, openshift5/lifecycle-agent-operator-bundle, +2 more
    affected: no fix available “Fix deferred”
  • Red Hat Hardened Images syft 1.51.0-0.1.hum1, grype 0.117.0-0.1.hum1
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.37% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/rclone/rclone/security/advisories/GHSA-6jcg-q3wp-x2f4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 7.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
bitnami rclone
>=1.72.0, <1.75.0
1.75.0

Affected products

  • rclone rclone

Classification

Weakness
  • CWE-129 Improper Validation of Array Index

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.