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Fencer Intel
medium 6.7

CVE-2026-4878 json

Libcap: libcap: privilege escalation via toctou race condition in cap_set_file()

published 7mo ago modified 7d ago also EUVD-2026-20910

cvss
6.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

A flaw was found in libcap. A local unprivileged user can exploit a Time-of-check-to-time-of-use (TOCTOU) race condition in the `cap_set_file()` function. This allows an attacker with write access to a parent directory to redirect file capability updates to an attacker-controlled file. By doing so, capabilities can be injected into or stripped from unintended executables, leading to privilege escalation.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:2.69-7.el10_1.1, 0:2.69-7.el10_2.1
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:2.69-7.el10_0.1
  • Red Hat Red Hat Enterprise Linux 8 0:2.48-6.el8_10.1
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:2.48-4.el8_6.1
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:2.48-4.el8_6.1
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:2.48-5.el8_8.1
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:2.48-5.el8_8.1
  • Red Hat Red Hat Enterprise Linux 9 0:2.48-10.el9_7.1, 0:2.48-10.el9_8.1
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:2.48-9.el9_2.1
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support 0:2.48-9.el9_4.1
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:2.48-9.el9_6.1
  • Red Hat Red Hat OpenShift Container Platform 4.12 412.86.202608241157-0
  • Red Hat Red Hat OpenShift Container Platform 4.13 413.92.202606160406-0
  • Red Hat Red Hat OpenShift Container Platform 4.14 414.92.202606231112-0
  • Red Hat Red Hat OpenShift Container Platform 4.15 415.92.202606030318-0
  • Red Hat Red Hat OpenShift Container Platform 4.16 416.94.202606051757-0
  • Red Hat Red Hat OpenShift Container Platform 4.17 417.94.202606250942-0
  • Red Hat Red Hat OpenShift Container Platform 4.18 418.94.202606051320-0
  • Red Hat Red Hat OpenShift Container Platform 4.19 4.19.9.6.202606031700-0
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.17 1791371069, 1791371080, 1791788287, 1791970484
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.18 1789029076, 1791459707, 1791459711, 1791459759, 1791966259
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 1790598593
  • Red Hat Cost Management 4 1780946239, 1783539156
  • Red Hat Red Hat AI Inference Server 3.2 1780681984
  • Red Hat Red Hat AI Inference Server 3.3 1782352847, 1782352919, 1782352950, 1782353093
  • Red Hat Red Hat Discovery 2 1778101579, 1778156756, 1782159791, 1782166952
  • Red Hat Red Hat Hardened Images 2.78-1.1.hum1
  • Red Hat Red Hat Insights proxy 1.5 1780420428
  • Red Hat Red Hat OpenShift AI 3.4 1790703542
  • Red Hat Red Hat OpenShift distributed tracing 3.9.3 1778056233, 1778056245, 1778056267
  • libcap2 Debian 12 1:2.66-4+deb12u3
  • libcap2 Debian 13 1:2.75-10+deb13u1
  • libcap2 Debian 14 1:2.78-1

debian advisories DEBIAN-CVE-2026-4878

  • libcap2 Ubuntu 22.04 LTS 1:2.44-1ubuntu0.22.04.3
  • libcap2 Ubuntu 24.04 LTS 1:2.66-5ubuntu2.4
  • libcap2 Ubuntu 25.10 1:2.75-7ubuntu2.2
  • libcap2 Ubuntu Pro 14.04 LTS 1:2.24-0ubuntu2+esm2
  • libcap2 Ubuntu Pro 16.04 LTS 1:2.24-12ubuntu0.1~esm2
  • libcap2 Ubuntu Pro 18.04 LTS 1:2.25-1.2ubuntu0.1~esm2
  • libcap2 Ubuntu Pro 20.04 LTS 1:2.32-1ubuntu0.2+esm1

ubuntu advisories UBUNTU-CVE-2026-4878

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libcap RHEL 9 2.48-10.el9_8.1
  • libcap RHEL 10.2 2.69-7.el10_2.1
  • libcap RHEL 8 2.48-6.el8_10.1
  • libcap RHEL 9 2.48-10.el9_7.1
  • libcap RHEL 10.1 2.69-7.el10_1.1
  • libcap hummingbird 1 2.78-1.1.hum1
  • libcap RHEL 8.6 EUS_LONG_LIFE, RHEL 8.6 AUS 2.48-4.el8_6.1
  • libcap RHEL 8.8 TUS, RHEL 8.8 E4S 2.48-5.el8_8.1

red hat advisories RHSA-2026:24346RHSA-2026:22957RHSA-2026:21254RHSA-2026:20595RHSA-2026:19458RHSA-2026:19456

  • libcap Linux Micro 6.2 2.73-160000.3.1
  • libcap Linux Micro 6.1 2.69-slfo.1.1_2.1
  • libcap Linux Micro 6.0 2.69-3.1
  • libcap SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 2.63-150400.3.6.1
  • libcap SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.26-14.12.1

suse advisories SUSE-SU-2026:21274-1SUSE-SU-2026:21257-1SUSE-SU-2026:21243-1SUSE-SU-2026:1433-1SUSE-SU-2026:1432-1

  • libcap openSUSE Leap 16.0 2.73-160000.3.1
  • libcap openSUSE Tumbleweed 2.78-1.1

opensuse advisories openSUSE-SU-2026:20613-1openSUSE-SU-2026:10536-1

  • libcap AlmaLinux 10 2.69-7.el10_2.1
  • libcap AlmaLinux 9 2.48-10.el9_8.1
  • libcap AlmaLinux 8 2.48-6.el8_10.1
  • libcap AlmaLinux 10 2.69-7.el10_1.1
  • libcap AlmaLinux 9 2.48-10.el9_7.1

almalinux advisories ALSA-2026:19130ALSA-2026:19346ALSA-2026:13285ALSA-2026:12423ALSA-2026:12441

  • libcap Rocky Linux 10 2.69-7.el10_1.1
  • libcap Rocky Linux 9 2.48-10.el9_7.1
  • libcap Rocky Linux 8 2.48-6.el8_10.1

rocky linux advisories RLSA-2026:19130RLSA-2026:19346RLSA-2026:13285RLSA-2026:12423RLSA-2026:12441

  • libcap Alpine 3.24, Alpine 3.23, Alpine 3.22 +2 more 2.78-r0

alpine advisories ALPINE-CVE-2026-4878

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • libcap Azure Linux 3.0 2.69-14

azure linux advisories AZL-82425

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-2026-4878 updated cvss 6.7

libcap: libcap: Privilege escalation via TOCTOU race condition in cap_set_file()

  • Red Hat Enterprise Linux 6 libcap, compat-libcap1 Red Hat Enterprise Linux 7 libcap, compat-libcap1
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift Container Platform 4 openshift4/ose-hypershift-rhel9
    under investigation
  • 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-operator-bundle 1791970484, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791371080
    fixed: vendor fix RHSA-2026:82888
  • 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-trust-manager-rhel9 1790598593
    fixed: vendor fix RHSA-2026:72502
  • Red Hat Cost Management 4 costmanagement/costmanagement-metrics-rhel9-operator 1780946239, costmanagement/costmanagement-metrics-rhel9-operator 1783539156
    fixed: vendor fix RHSA-2026:39981
  • Red Hat AI Inference Server 3.2 rhaiis/model-opt-cuda-rhel9 1780681984
    fixed: vendor fix RHSA-2026:25096
  • Red Hat AI Inference Server 3.3 rhaiis/vllm-cuda-rhel9 1782352847, rhaiis/vllm-rocm-rhel9 1782353093, rhaiis/vllm-spyre-rhel9 1782352919, rhaiis/model-opt-cuda-rhel9 1782352950
    fixed: vendor fix RHSA-2026:30078
show 31 more
  • Red Hat Discovery 2 discovery 1778101579, discovery 1778156756, discovery/discovery-ui-rhel9 1782166952, discovery/discovery-server-rhel9 1782159791
    fixed: vendor fix RHSA-2026:14937
  • Red Hat Enterprise Linux AppStream (v. 9) libcap-devel 2.48-10.el9_7.1, libcap-devel 2.48-10.el9_8.1, libcap-debuginfo 2.48-10.el9_7.1, libcap-debuginfo 2.48-10.el9_8.1, libcap-debugsource 2.48-10.el9_7.1, libcap-debugsource 2.48-10.el9_8.1
    fixed: vendor fix RHSA-2026:12441
  • Red Hat Enterprise Linux AppStream (v. 10) libcap-devel 2.69-7.el10_1.1, libcap-devel 2.69-7.el10_2.1, libcap-debuginfo 2.69-7.el10_1.1, libcap-debuginfo 2.69-7.el10_2.1, libcap-debugsource 2.69-7.el10_1.1, libcap-debugsource 2.69-7.el10_2.1
    fixed: vendor fix RHSA-2026:12423
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) libcap-devel 2.48-9.el9_2.1, libcap-debuginfo 2.48-9.el9_2.1, libcap-debugsource 2.48-9.el9_2.1
    fixed: vendor fix RHSA-2026:21254
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) libcap-devel 2.69-7.el10_0.1, libcap-debuginfo 2.69-7.el10_0.1, libcap-debugsource 2.69-7.el10_0.1
    fixed: vendor fix RHSA-2026:19456
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) libcap-devel 2.48-9.el9_4.1, libcap-debuginfo 2.48-9.el9_4.1, libcap-debugsource 2.48-9.el9_4.1
    fixed: vendor fix RHSA-2026:20595
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) libcap-devel 2.48-9.el9_6.1, libcap-debuginfo 2.48-9.el9_6.1, libcap-debugsource 2.48-9.el9_6.1
    fixed: vendor fix RHSA-2026:19458
  • Red Hat Enterprise Linux BaseOS (v. 8) libcap 2.48-6.el8_10.1
    fixed: vendor fix RHSA-2026:13285
  • Red Hat Enterprise Linux BaseOS (v. 9) libcap 2.48-10.el9_7.1, libcap 2.48-10.el9_8.1
    fixed: vendor fix RHSA-2026:12441
  • Red Hat Enterprise Linux BaseOS (v. 10) libcap 2.69-7.el10_1.1, libcap 2.69-7.el10_2.1
    fixed: vendor fix RHSA-2026:12423
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) libcap 2.48-4.el8_6.1
    fixed: vendor fix RHSA-2026:24346
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) libcap 2.48-5.el8_8.1
    fixed: vendor fix RHSA-2026:22957
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) libcap 2.48-9.el9_2.1
    fixed: vendor fix RHSA-2026:21254
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) libcap 2.69-7.el10_0.1
    fixed: vendor fix RHSA-2026:19456
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) libcap 2.48-9.el9_4.1
    fixed: vendor fix RHSA-2026:20595
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) libcap 2.48-9.el9_6.1
    fixed: vendor fix RHSA-2026:19458
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) libcap 2.48-4.el8_6.1
    fixed: vendor fix RHSA-2026:24346
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) libcap 2.48-5.el8_8.1
    fixed: vendor fix RHSA-2026:22957
  • Red Hat Hardened Images libcap 2.78-1.1.hum1
    fixed: vendor fix RHSA-2026:7473
  • Red Hat Insights proxy 1.5 insights-proxy/insights-proxy-container-rhel9 1780420428
    fixed: vendor fix RHSA-2026:22634
  • Red Hat OpenShift AI 3.4 rhai/base-image-neuron-rhel9 1790703542
    fixed: vendor fix RHSA-2026:74674
  • Red Hat OpenShift Container Platform 4.12 rhcos 412.86.202608241157
    fixed: vendor fix RHSA-2026:59831
  • Red Hat OpenShift Container Platform 4.13 rhcos 413.92.202606160406
    fixed: vendor fix RHSA-2026:26542
  • Red Hat OpenShift Container Platform 4.14 rhcos 414.92.202606231112
    fixed: vendor fix RHSA-2026:28887
  • Red Hat OpenShift Container Platform 4.15 rhcos 415.92.202606030318
    fixed: vendor fix RHSA-2026:23233
  • Red Hat OpenShift Container Platform 4.16 rhcos 416.94.202606051757
    fixed: vendor fix RHSA-2026:25044
  • Red Hat OpenShift Container Platform 4.17 rhcos 417.94.202606250942
    fixed: vendor fix RHSA-2026:34098
  • Red Hat OpenShift Container Platform 4.18 rhcos 418.94.202606051320
    fixed: vendor fix RHSA-2026:25181
  • Red Hat OpenShift Container Platform 4.19 rhcos 4.19.9.6.202606031700
    fixed: vendor fix RHSA-2026:23245
  • Red Hat OpenShift distributed tracing 3.9.3 rhosdt 1778056233, rhosdt 1778056245, rhosdt 1778056267
    fixed: vendor fix RHSA-2026:14162
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1779798159, rhui5/rhua-rhel9 1779798222, rhui5/haproxy-rhel9 1779798164, rhui5/rhua-tp-rhel9 1787241260, rhui5/installer-rhel9 1779798165, rhui5/installer-tp-rhel9 1787135742, +1 more
    fixed: vendor fix RHSA-2026:58981

4 more not affected in the full advisory

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
7mo ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • openwall.com http://www.openwall.com/lists/oss-security/2026/04/09/5 referenced PoC, tagged "exploit" by a source, unverified
  • openwall.com http://www.openwall.com/lists/oss-security/2026/04/09/6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 6.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
CISA ADP 3.1 6.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat OpenShift Container Platform 4.12
  • Red Hat Red Hat OpenShift Container Platform 4.13
  • Red Hat Red Hat OpenShift Container Platform 4.14
  • Red Hat Red Hat OpenShift Container Platform 4.15
  • Red Hat Red Hat OpenShift Container Platform 4.16
  • Red Hat Red Hat OpenShift Container Platform 4.17
  • Red Hat Red Hat OpenShift Container Platform 4.18
  • Red Hat Red Hat OpenShift Container Platform 4.19
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.17
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.18
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20
  • Red Hat Cost Management 4
  • Red Hat Red Hat AI Inference Server 3.2
  • Red Hat Red Hat AI Inference Server 3.3
  • Red Hat Red Hat Discovery 2
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Insights proxy 1.5
  • Red Hat Red Hat OpenShift AI 3.4
  • Red Hat Red Hat OpenShift distributed tracing 3.9.3
  • Red Hat Red Hat Update Infrastructure 5
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat OpenShift Container Platform 4

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.

CPEs and fixed versions use Anchore's correction of NVD's data: As so often is the case, NVD has incorrect data.