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Fencer Intel
medium 6.3

CVE-2026-54370 json

acl < 2.4.0 TOCTOU Symlink Traversal via getfacl/setfacl/chacl

published 4mo ago modified 17d ago also EUVD-2026-40086

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

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.

Patch / fix

  • acl project acl 2.4.0
  • acl Debian 14 2.4.0-1

debian advisories DEBIAN-CVE-2026-54370

  • acl RHEL 8 2.4.0-1.el8_10
  • libacl RHEL 8 2.4.0-1.el8_10
  • acl RHEL 10.2 2.4.0-1.el10_2
  • libacl RHEL 10.2 2.4.0-1.el10_2
  • acl RHEL 9 2.4.0-1.el9_8
  • libacl RHEL 9 2.4.0-1.el9_8
  • acl hummingbird 1 2.4.0-0.1.hum1
  • libacl hummingbird 1 2.4.0-0.1.hum1

red hat advisories RHSA-2026:43420RHSA-2026:42739RHSA-2026:42736RHSA-2026:34351

  • attr SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 2.6.0-150000.4.3.1
  • acl SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 2.4.0-150000.4.6.1
  • attr SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 2.6.0-160000.1.1
  • acl SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 2.4.0-160000.1.1

suse advisories SUSE-SU-2026:4176-1SUSE-SU-2026:23670-1SUSE-SU-2026:23705-1SUSE-SU-2026:23726-1

  • attr openSUSE Leap 16.0 2.6.0-160000.1.1
  • acl openSUSE Leap 16.0 2.4.0-160000.1.1
  • acl openSUSE Tumbleweed 2.4.0-1.1

opensuse advisories openSUSE-SU-2026:21832-1openSUSE-SU-2026:11312-1

  • acl AlmaLinux 8 2.4.0-1.el8_10
  • libacl AlmaLinux 8 2.4.0-1.el8_10
  • acl AlmaLinux 9 2.4.0-1.el9_8
  • libacl AlmaLinux 9 2.4.0-1.el9_8
  • acl AlmaLinux 10 2.4.0-1.el10_2
  • libacl AlmaLinux 10 2.4.0-1.el10_2

almalinux advisories ALSA-2026:43420ALSA-2026:42736ALSA-2026:42739

  • acl Rocky Linux 8 2.4.0-1.el8_10
  • acl Rocky Linux 10 2.4.0-1.el10_2
  • acl Rocky Linux 9 2.4.0-1.el9_8

rocky linux advisories RLSA-2026:43420RLSA-2026:42739RLSA-2026:42736

  • acl Azure Linux 3.0 2.4.0-1

azure linux advisories AZL-91394

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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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-2026-54370 updated cvss 6.3

acl: TOCTOU Symlink Traversal via getfacl/setfacl

  • Red Hat Enterprise Linux 6 acl, libacl Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: no fix available “Fix deferred”
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.17 cert-manager/cert-manager-operator-rhel9 1791788287, cert-manager/jetstack-cert-manager-rhel9 1791371069, cert-manager/cert-manager-istio-csr-rhel9 1791378395, cert-manager/cert-manager-operator-bundle 1791970484, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791371080
    fixed: vendor fix RHSA-2026:82336
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.18 cert-manager/cert-manager-operator-rhel9 1789029076, cert-manager/jetstack-cert-manager-rhel9 1791459711, cert-manager/cert-manager-istio-csr-rhel9 1791459759, cert-manager/cert-manager-operator-bundle 1791966259, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791459707
    fixed: vendor fix RHSA-2026:82354
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/cert-manager-operator-rhel9 1790272426, cert-manager/cert-manager-operator-rhel9 1790589855, cert-manager/jetstack-cert-manager-rhel9 1790223279, cert-manager/jetstack-cert-manager-rhel9 1790589912, cert-manager/cert-manager-istio-csr-rhel9 1790223719, cert-manager/cert-manager-istio-csr-rhel9 1790589914, +2 more
    fixed: vendor fix RHSA-2026:72475
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1784821750
    fixed: vendor fix RHSA-2026:46836
  • Red Hat Enterprise Linux AppStream (v. 9) acl-debuginfo 2.4.0-1.el9_8, acl-debugsource 2.4.0-1.el9_8
    fixed: vendor fix RHSA-2026:42736
  • Red Hat Enterprise Linux AppStream (v. 10) acl-debuginfo 2.4.0-1.el10_2, acl-debugsource 2.4.0-1.el10_2
    fixed: vendor fix RHSA-2026:42739
  • Red Hat Enterprise Linux BaseOS (v. 8) acl 2.4.0-1.el8_10
    fixed: vendor fix RHSA-2026:43420
show 8 more
  • Red Hat Enterprise Linux BaseOS (v. 9) acl 2.4.0-1.el9_8
    fixed: vendor fix RHSA-2026:42736
  • Red Hat Enterprise Linux BaseOS (v. 10) acl 2.4.0-1.el10_2
    fixed: vendor fix RHSA-2026:42739
  • Red Hat Enterprise Linux Server (v. 7 ELS) acl 2.4.0-0.el7_9.1
    fixed: vendor fix RHSA-2026:98129
  • Red Hat Hardened Images acl 2.4.0-0.1.hum1, libacl 2.4.0-0.1.hum1
    fixed: vendor fix RHSA-2026:34351
  • Red Hat Insights proxy 1.5 insights-proxy/insights-proxy-container-rhel9 1786433656
    fixed: vendor fix RHSA-2026:53371
  • Red Hat OpenShift distributed tracing 3.10.1 rhosdt/opentelemetry-collector-rhel9 1785704636
    fixed: vendor fix RHSA-2026:50205
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1784794778, rhui5/rhua-rhel9 1784795076, rhui5/haproxy-rhel9 1784795112, rhui5/rhua-tp-rhel9 1787241260, rhui5/installer-rhel9 1784794289, rhui5/installer-tp-rhel9 1787135742, +2 more
    fixed: vendor fix RHSA-2026:44481
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/jetstack-cert-manager-acmesolver-rhel9 1790223630 Red Hat Discovery 2 discovery/discovery-server-rhel9 1784821670 Red Hat Enterprise Linux AppStream (v. 9) libacl-devel 2.4.0-1.el9_8, libacl-debuginfo 2.4.0-1.el9_8 Red Hat Enterprise Linux AppStream (v. 10) libacl-devel 2.4.0-1.el10_2, libacl-debuginfo 2.4.0-1.el10_2 Red Hat Enterprise Linux BaseOS (v. 8) libacl 2.4.0-1.el8_10 Red Hat Enterprise Linux BaseOS (v. 9) libacl 2.4.0-1.el9_8
    +4 more products
    Red Hat Enterprise Linux BaseOS (v. 10) libacl 2.4.0-1.el10_2 Red Hat Enterprise Linux Server (v. 7 ELS) libacl 2.4.0-0.el7_9.1 Red Hat OpenShift distributed tracing 3.10.1 rhosdt/opentelemetry-rhel9-operator 1785704547, rhosdt/opentelemetry-operator-bundle 1785744179, rhosdt/opentelemetry-target-allocator-rhel9 1785704551 Red Hat Update Infrastructure 5 rhui5/cds-tp-rhel9 1787241206
    not affected: vulnerable code 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
none
Automatable
no
Technical impact
total
Assessed
4mo ago

Exploit prediction

0.09% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 7.2 CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA 3.1 6.3 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
CNA 4.0 7.2 CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/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 products

  • acl project acl

Classification

Weakness
  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition

References

Sources

Fencer Intel 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.