# CVE-2021-40153: squashfs-tools: SquashFS is a highly compressed read-only file system for Linux

CVE-2021-40153 is fixed in squashfs-tools on 1 platform, first by squashfs-tools 1:4.3-6ubuntu0.18.04.3, released August 27, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-40153
- Priority: High
- CVSS: 8.1 (Moderate)
- EPSS: 0.0250
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 27, 2021

## Description

SquashFS is a highly compressed read-only file system for Linux. These packages contain the utilities for manipulating squashfs file systems.  Security Fix(es):  * squashfs-tools: unvalidated filepaths allow writing outside of destination (CVE-2021-40153)  * squashfs-tools: possible Directory Traversal via symbolic link (CVE-2021-41072)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.  Additional Changes:  For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.10 Release Notes linked from the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | squashfs-tools RHEL 8 | 0:4.3-21.el8 | [RHSA-2024:3139](https://patchblox.com/security/data/fix/linux/rhsa-2024-3139.md) | May 22, 2024 |
| Linux | squashfs-tools RHEL 9 | 0:4.4-10.git1.el9 | [RHSA-2024:2396](https://patchblox.com/security/data/fix/linux/rhsa-2024-2396.md) | Apr 30, 2024 |
| Linux | squashfs-tools Ubuntu 18.04.6 LTS (bionic) | 1:4.3-6ubuntu0.18.04.3 | [squashfs-tools 1:4.3-6ubuntu0.18.04.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-squashfs-tools-1-4.3-6ubuntu0.18.04.3.md) | Aug 27, 2021 |
| Linux | squashfs-tools Ubuntu 20.04 LTS (focal) | 1:4.4-1ubuntu0.1 | [squashfs-tools 1:4.4-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-squashfs-tools-1-4.4-1ubuntu0.1.md) | Aug 27, 2021 |
| Linux | squashfs-tools almalinux 8 | 4.3-21.el8 | [ALSA-2024:3139](https://patchblox.com/security/data/fix/linux/alsa-2024-3139.md) | May 22, 2024 |
| Linux | squashfs-tools almalinux 9 | 4.4-10.git1.el9 | [ALSA-2024:2396](https://patchblox.com/security/data/fix/linux/alsa-2024-2396.md) | Apr 30, 2024 |
| Linux | squashfs-tools ol 8 | 0:4.3-21.el8 | [ELSA-2024-3139](https://patchblox.com/security/data/fix/linux/elsa-2024-3139.md) | May 23, 2024 |
| Linux | squashfs-tools ol 9 | 0:4.4-10.git1.el9 | [ELSA-2024-2396](https://patchblox.com/security/data/fix/linux/elsa-2024-2396.md) | May 2, 2024 |
| Linux | squashfs-tools rocky 8 | 0:4.3-21.el8 | [RLSA-2024:3139](https://patchblox.com/security/data/fix/linux/rlsa-2024-3139.md) | Jun 14, 2024 |
| Linux | squashfs-tools rocky 9 | 0:4.4-10.git1.el9 | [RLSA-2024:2396](https://patchblox.com/security/data/fix/linux/rlsa-2024-2396.md) | May 7, 2025 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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