Skip to content
Fencer Vulns
medium 6.5

CVE-2026-4426 json

Libarchive: libarchive: denial of service via malformed iso file processing

published 2026-03-19 7 mo ago modified 2026-11-06 3 d ago also EUVD-2026-13099

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

A flaw was found in libarchive. An Undefined Behavior vulnerability exists in the zisofs decompression logic, caused by improper validation of a field (`pz_log2_bs`) read from ISO9660 Rock Ridge extensions. A remote attacker can exploit this by supplying a specially crafted ISO file. This can lead to incorrect memory allocation and potential application crashes, resulting in a denial-of-service (DoS) condition.

Patch / fix

  • Red Hat Red Hat Hardened Images 3.8.7-1.hum1
  • libarchive Debian 12 3.6.2-1+deb12u4
  • libarchive Debian 13 3.7.4-4+deb13u1
  • libarchive Debian 14 3.8.7-1

debian advisories DEBIAN-CVE-2026-4426

  • libarchive Ubuntu 22.04 LTS 3.6.0-1ubuntu1.7
  • libarchive Ubuntu 24.04 LTS 3.7.2-2ubuntu0.7
  • libarchive Ubuntu 25.10 3.7.7-0ubuntu3.2
  • libarchive Ubuntu 26.04 LTS 3.8.5-1ubuntu2.1
  • libarchive Ubuntu Pro 14.04 LTS 3.1.2-7ubuntu2.8+esm5
  • libarchive Ubuntu Pro 16.04 LTS 3.1.2-11ubuntu0.16.04.8+esm3
  • libarchive Ubuntu Pro 18.04 LTS 3.2.2-3.1ubuntu0.7+esm3
  • libarchive Ubuntu Pro 20.04 LTS 3.4.0-2ubuntu1.5+esm2

ubuntu advisories UBUNTU-CVE-2026-4426

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

  • libarchive hummingbird 1 3.8.7-1.hum1

red hat advisories RHSA-2026:8944

  • libarchive SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +8 more 3.5.1-150400.3.24.1
  • libarchive SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 +1 more 3.7.2-150600.3.20.1
  • libarchive Linux Micro 6.1 3.7.4-slfo.1.1_4.1
  • libarchive Linux Micro 6.0 3.6.2-6.1
  • libarchive SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 3.3.3-32.17.1

suse advisories SUSE-SU-2026:2747-1SUSE-SU-2026:2599-1SUSE-SU-2026:2490-1SUSE-SU-2026:22248-1SUSE-SU-2026:22241-1

  • libarchive Azure Linux 3.0 3.7.7-6

azure linux advisories AZL-80400

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

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-2026-4426 updated cvss 6.5

libarchive: libarchive: Denial of Service via malformed ISO file processing

  • Red Hat Enterprise Linux 6 libarchive
    affected: workaround, no fix planned “To mitigate this issue, avoid processing untrusted ISO9660 images with `libarchive`. Restricting the sources of ISO files and ensuring they originate from trusted entities can prevent exploitation.”
  • Red Hat Enterprise Linux 7 bsdtar, bsdcpio, libarchive Red Hat Enterprise Linux 8 bsdtar, libarchive Red Hat Enterprise Linux 9 bsdtar, libarchive Red Hat Enterprise Linux 10 libarchive Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “To mitigate this issue, avoid processing untrusted ISO9660 images with `libarchive`. Restricting the sources of ISO files and ensuring they originate from trusted entities can prevent exploitation.”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-core-bff-rhel9, rhoai/odh-dashboard-rhel9, rhoai/odh-mod-arch-maas-rhel9, rhoai/odh-mod-arch-automl-rhel9, rhoai/odh-mod-arch-gen-ai-rhel9, rhoai/odh-mod-arch-mlflow-rhel9, +6 more
    under investigation
  • Red Hat Hardened Images libarchive 3.8.7-1.hum1
    fixed: vendor fix “To mitigate this issue, avoid processing untrusted ISO9660 images with `libarchive`. Restricting the sources of ISO files and ensuring they originate from trusted entities can prevent exploitation.” RHSA-2026:8944
  • Red Hat Hardened Images bsdcat 3.8.7-1.hum1, bsdtar 3.8.7-1.hum1, bsdcpio 3.8.7-1.hum1, bsdunzip 3.8.7-1.hum1 Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-kube-rbac-proxy-rhel9, rhoai/odh-maas-controller-rhel9, rhoai/odh-mlflow-operator-rhel9, rhoai/odh-model-controller-rhel9, rhoai/odh-ogx-k8s-operator-rhel9, +14 more
    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
partial
Assessed
7 mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift AI (RHOAI)
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness
  • CWE-1335 Incorrect Bitwise Shift of Integer

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.