# CVE-2026-4426: Libarchive: libarchive: denial of service via malformed iso file processing Status: published. Published: 2026-03-19. Updated: 2026-11-06. 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. ## Remediation - workaround: 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. (source: CNA: redhat) - fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: secalert@redhat.com) — https://github.com/libarchive/libarchive/pull/2897 ## Affected products and versions - Red Hat / Red Hat Hardened Images (libarchive-main): ≥ 3.8.7-1.hum1; < * (unaffected, rpm). Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 10 (libarchive): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 6 (libarchive): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 7 (libarchive): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 8 (libarchive): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat Enterprise Linux 9 (libarchive): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-ai-gateway-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-core-bff-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-dashboard-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-dashboard-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-data-science-pipelines-operator-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-kf-notebook-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-kserve-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-kserve-llmisvc-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-kserve-module-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-kuberay-operator-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-kube-rbac-proxy-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-llama-stack-k8s-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-maas-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mlflow-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mlflow-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-agent-ops-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-automl-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-autorag-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-eval-hub-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-gen-ai-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-maas-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-mlflow-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-mod-arch-model-registry-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-model-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-model-registry-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-model-serving-api-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-notebook-controller-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-ogx-k8s-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-ogx-module-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-training-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-trustyai-service-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift AI (RHOAI) (rhoai/odh-workbenches-operator-rhel9): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat - Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat ## NVD configuration conditions Affected CPE matches depend on the following AND/OR and negation conditions: ```json [ { "negate": false, "nodes": [ { "cpeMatch": [ { "criteria": "cpe:2.3:a:libarchive:libarchive:-:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "vulnerable": true }, { "criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*", "vulnerable": true } ], "negate": false, "operator": "OR" } ], "operator": "OR" } ] ``` ## Severity and prioritization - CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: CNA: redhat - CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H; source: NVD: secalert@redhat.com - CISA KEV: No listing in collected sources - EPSS: 0.32% as of 2026-11-05; percentile 24.81% - SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP - Weaknesses: CWE-1335 ## Exploit evidence No exploit evidence in collected sources. This is not proof of no exploitation. ## References - https://access.redhat.com/errata/RHSA-2026:8944 (CNA: redhat; vendor-advisory, x_refsource_REDHAT) - https://access.redhat.com/security/cve/CVE-2026-4426 (CNA: redhat; vdb-entry, x_refsource_REDHAT) - https://bugzilla.redhat.com/show_bug.cgi?id=2449010 (CNA: redhat; issue-tracking, x_refsource_REDHAT) - https://github.com/libarchive/libarchive/pull/2897 (CNA: redhat) - https://access.redhat.com/errata/RHSA-2026:8944 (secalert@redhat.com) - https://access.redhat.com/security/cve/CVE-2026-4426 (secalert@redhat.com; Third Party Advisory) - https://bugzilla.redhat.com/show_bug.cgi?id=2449010 (secalert@redhat.com; Issue Tracking, Third Party Advisory) - https://github.com/libarchive/libarchive/pull/2897 (secalert@redhat.com; Issue Tracking, Patch) ## Provenance - CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-4426; retrieved 2026-11-06; source updated 2026-11-06 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4426; retrieved 2026-11-06; source updated 2026-11-05 - FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-4426; retrieved 2026-11-05; source updated Not reported Revision: 8772690d8102081d54bcecb803f228b36d866c1d1f529f958422dbf7e7aaa145 Canonical: https://y2.dev/cve/CVE-2026-4426 ## Agent and API access Public CVE pages, Markdown, and JSON are free to read without an account or API key. - Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end. - WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers. - Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}. - Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer . Setup: https://y2.dev/docs/api/create-key. - x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402. - OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json. Collected public records only. Check source status for coverage and freshness.