# CVE-2026-54370: acl: acl before version 2.4.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability that allows lo...

CVE-2026-54370 is fixed in 7 products on 1 platform, first by DEBIAN-CVE-2026-54370, released July 3, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-54370
- Priority: High
- CVSS: 7.1 (moderate)
- EPSS: 0.0009
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 29, 2026

## Description

acl before version 2.4.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability that allows local attackers to escalate privileges by replacing a pathname component with a symbolic link between an lstat() check and subsequent symlink-following operations such as stat(), chown(), chmod(), acl_get_file(), and acl_set_file(). Attackers who control a pathname component can redirect file access control list operations to arbitrary files when getfacl, setfacl, or chacl is invoked by a privileged process over an attacker-controlled path, resulting in local privilege escalation.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | acl Debian 14 | 2.4.0-1 | [DEBIAN-CVE-2026-54370](https://patchblox.com/security/data/fix/linux/debian-cve-2026-54370.md) | Jul 3, 2026 |
| Linux | acl Fedora 43 | 2.4.0-1.fc43 | [FEDORA-2026-67504C329B](https://patchblox.com/security/data/fix/linux/fedora-2026-67504c329b.md) | Jul 9, 2026 |
| Linux | acl RHEL 10 | 2.4.0-1.el10_2 | [RHSA-2026:42739](https://patchblox.com/security/data/fix/linux/rhsa-2026-42739.md) | Jul 22, 2026 |
| Linux | acl RHEL 8 | 0:2.4.0-1.el8_10 | [RHSA-2026:43420](https://patchblox.com/security/data/fix/linux/rhsa-2026-43420.md) | Jul 23, 2026 |
| Linux | acl RHEL 9 | 0:2.4.0-1.el9_8 | [RHSA-2026:42736](https://patchblox.com/security/data/fix/linux/rhsa-2026-42736.md) | Jul 22, 2026 |
| Linux | acl almalinux 10 | 2.4.0-1.el10_2 | [ALSA-2026:42739](https://patchblox.com/security/data/fix/linux/alsa-2026-42739.md) | Jul 21, 2026 |
| Linux | acl almalinux 8 | 2.4.0-1.el8_10 | [ALSA-2026:43420](https://patchblox.com/security/data/fix/linux/alsa-2026-43420.md) | Jul 22, 2026 |
| Linux | acl almalinux 9 | 2.4.0-1.el9_8 | [ALSA-2026:42736](https://patchblox.com/security/data/fix/linux/alsa-2026-42736.md) | Jul 21, 2026 |
| Linux | acl amzn 2023 | 2.4.0-1.amzn2023.0.1 | [ALAS2023-2026-1986](https://patchblox.com/security/data/fix/linux/alas2023-2026-1986.md) | Jul 20, 2026 |
| Linux | acl ol 10 | 0:2.4.0-1.el10_2 | [ELSA-2026-42739](https://patchblox.com/security/data/fix/linux/elsa-2026-42739.md) | Jul 21, 2026 |
| Linux | acl ol 8 | 0:2.4.0-1.el8_10 | [ELSA-2026-43420](https://patchblox.com/security/data/fix/linux/elsa-2026-43420.md) | Jul 22, 2026 |
| Linux | acl ol 9 | 0:2.4.0-1.el9_8 | [ELSA-2026-42736](https://patchblox.com/security/data/fix/linux/elsa-2026-42736.md) | Jul 21, 2026 |
| Linux | acl opensuse-leap 16.0 | 2.4.0-160000.1.1 | [OPENSUSE-SU-2026:21832-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21832-1.md) | Sep 11, 2026 |
| Linux | acl rocky 10 | 0:2.4.0-1.el10_2 | [RLSA-2026:42739](https://patchblox.com/security/data/fix/linux/rlsa-2026-42739.md) | Jul 22, 2026 |
| Linux | acl rocky 8 | 0:2.4.0-1.el8_10 | [RLSA-2026:43420](https://patchblox.com/security/data/fix/linux/rlsa-2026-43420.md) | Jul 23, 2026 |
| Linux | acl rocky 9 | 0:2.4.0-1.el9_8 | [RLSA-2026:42736](https://patchblox.com/security/data/fix/linux/rlsa-2026-42736.md) | Jul 22, 2026 |
| Linux | acl sles 15.6 | 2.4.0-150000.4.6.1 | [SUSE-SU-2026:4176-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4176-1.md) | Sep 14, 2026 |
| Linux | acl sles 15.7 | 2.4.0-150000.4.6.1 | [SUSE-SU-2026:4176-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4176-1.md) | Sep 14, 2026 |
| Linux | acl sles 16.0 | 2.4.0-160000.1.1 | [SUSE-SU-2026:23726-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23726-1.md) | Sep 11, 2026 |
| Linux | acl-debuginfo Fedora 43 | 2.4.0-1.fc43 | [FEDORA-2026-67504C329B](https://patchblox.com/security/data/fix/linux/fedora-2026-67504c329b.md) | Jul 9, 2026 |
| Linux | acl-debuginfo amzn 2023 | 2.4.0-1.amzn2023.0.1 | [ALAS2023-2026-1986](https://patchblox.com/security/data/fix/linux/alas2023-2026-1986.md) | Jul 20, 2026 |
| Linux | acl-debugsource Fedora 43 | 2.4.0-1.fc43 | [FEDORA-2026-67504C329B](https://patchblox.com/security/data/fix/linux/fedora-2026-67504c329b.md) | Jul 9, 2026 |
| Linux | acl-debugsource amzn 2023 | 2.4.0-1.amzn2023.0.1 | [ALAS2023-2026-1986](https://patchblox.com/security/data/fix/linux/alas2023-2026-1986.md) | Jul 20, 2026 |
| Linux | attr opensuse-leap 16.0 | 2.6.0-160000.1.1 | [OPENSUSE-SU-2026:21832-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21832-1.md) | Sep 11, 2026 |
| Linux | attr sles 15.6 | 2.6.0-150000.4.3.1 | [SUSE-SU-2026:4176-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4176-1.md) | Sep 14, 2026 |
| Linux | attr sles 15.7 | 2.6.0-150000.4.3.1 | [SUSE-SU-2026:4176-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4176-1.md) | Sep 14, 2026 |
| Linux | attr sles 16.0 | 2.6.0-160000.1.1 | [SUSE-SU-2026:23726-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23726-1.md) | Sep 11, 2026 |
| Linux | libacl Fedora 43 | 2.4.0-1.fc43 | [FEDORA-2026-67504C329B](https://patchblox.com/security/data/fix/linux/fedora-2026-67504c329b.md) | Jul 9, 2026 |
| Linux | libacl RHEL 8 | 0:2.4.0-1.el8_10 | [RHSA-2026:43420](https://patchblox.com/security/data/fix/linux/rhsa-2026-43420.md) | Jul 23, 2026 |
| Linux | libacl RHEL 9 | 0:2.4.0-1.el9_8 | [RHSA-2026:42736](https://patchblox.com/security/data/fix/linux/rhsa-2026-42736.md) | Jul 22, 2026 |
| Linux | libacl almalinux 10 | 2.4.0-1.el10_2 | [ALSA-2026:42739](https://patchblox.com/security/data/fix/linux/alsa-2026-42739.md) | Jul 21, 2026 |
| Linux | libacl almalinux 8 | 2.4.0-1.el8_10 | [ALSA-2026:43420](https://patchblox.com/security/data/fix/linux/alsa-2026-43420.md) | Jul 22, 2026 |
| Linux | libacl almalinux 9 | 2.4.0-1.el9_8 | [ALSA-2026:42736](https://patchblox.com/security/data/fix/linux/alsa-2026-42736.md) | Jul 21, 2026 |
| Linux | libacl amzn 2023 | 2.4.0-1.amzn2023.0.1 | [ALAS2023-2026-1986](https://patchblox.com/security/data/fix/linux/alas2023-2026-1986.md) | Jul 20, 2026 |
| Linux | libacl ol 10 | 0:2.4.0-1.el10_2 | [ELSA-2026-42739](https://patchblox.com/security/data/fix/linux/elsa-2026-42739.md) | Jul 21, 2026 |
| Linux | libacl ol 8 | 0:2.4.0-1.el8_10 | [ELSA-2026-43420](https://patchblox.com/security/data/fix/linux/elsa-2026-43420.md) | Jul 22, 2026 |
| Linux | libacl ol 9 | 0:2.4.0-1.el9_8 | [ELSA-2026-42736](https://patchblox.com/security/data/fix/linux/elsa-2026-42736.md) | Jul 21, 2026 |
| Linux | libacl-debuginfo Fedora 43 | 2.4.0-1.fc43 | [FEDORA-2026-67504C329B](https://patchblox.com/security/data/fix/linux/fedora-2026-67504c329b.md) | Jul 9, 2026 |
| Linux | libacl-debuginfo amzn 2023 | 2.4.0-1.amzn2023.0.1 | [ALAS2023-2026-1986](https://patchblox.com/security/data/fix/linux/alas2023-2026-1986.md) | Jul 20, 2026 |
| Linux | libacl-devel Fedora 43 | 2.4.0-1.fc43 | [FEDORA-2026-67504C329B](https://patchblox.com/security/data/fix/linux/fedora-2026-67504c329b.md) | Jul 9, 2026 |
| Linux | libacl-devel RHEL 8 | 0:2.4.0-1.el8_10 | [RHSA-2026:43420](https://patchblox.com/security/data/fix/linux/rhsa-2026-43420.md) | Jul 23, 2026 |
| Linux | libacl-devel RHEL 9 | 0:2.4.0-1.el9_8 | [RHSA-2026:42736](https://patchblox.com/security/data/fix/linux/rhsa-2026-42736.md) | Jul 22, 2026 |
| Linux | libacl-devel almalinux 10 | 2.4.0-1.el10_2 | [ALSA-2026:42739](https://patchblox.com/security/data/fix/linux/alsa-2026-42739.md) | Jul 21, 2026 |
| Linux | libacl-devel almalinux 8 | 2.4.0-1.el8_10 | [ALSA-2026:43420](https://patchblox.com/security/data/fix/linux/alsa-2026-43420.md) | Jul 22, 2026 |
| Linux | libacl-devel almalinux 9 | 2.4.0-1.el9_8 | [ALSA-2026:42736](https://patchblox.com/security/data/fix/linux/alsa-2026-42736.md) | Jul 21, 2026 |
| Linux | libacl-devel amzn 2023 | 2.4.0-1.amzn2023.0.1 | [ALAS2023-2026-1986](https://patchblox.com/security/data/fix/linux/alas2023-2026-1986.md) | Jul 20, 2026 |
| Linux | libacl-devel ol 10 | 0:2.4.0-1.el10_2 | [ELSA-2026-42739](https://patchblox.com/security/data/fix/linux/elsa-2026-42739.md) | Jul 21, 2026 |
| Linux | libacl-devel ol 8 | 0:2.4.0-1.el8_10 | [ELSA-2026-43420](https://patchblox.com/security/data/fix/linux/elsa-2026-43420.md) | Jul 22, 2026 |
| Linux | libacl-devel ol 9 | 0:2.4.0-1.el9_8 | [ELSA-2026-42736](https://patchblox.com/security/data/fix/linux/elsa-2026-42736.md) | Jul 21, 2026 |

---

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