Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-07-10T00:00:00 adm-zip: adm-zip: Denial of Service via crafted ZIP file leading to excessive memory allocation 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H CWE-409

adm-zip before 0.5.18 is vulnerable to denial of service via a crafted ZIP file with a manipulated uncompressed size header field. In zipEntry.js line 103, Buffer.alloc(_centralHeader.size) allocates memory based on the declared uncompressed size from the ZIP central directory header without validating it against the actual compressed data size or imposing any upper bound. The size value is read directly from the binary header at entryHeader.js line 266 with no bounds check. An attacker can craft a ~120-byte ZIP file that declares ~4GB uncompressed size, causing a memory allocation amplification ratio of over 33 million to 1. The allocation occurs before CRC validation, so the malicious payload cannot be rejected early. All extraction and read methods are affected: readFile(), readAsText(), extractEntryTo(), extractAllTo(), extractAllToAsync(), test(), and entry.getData(). Any application accepting untrusted ZIP files via adm-zip is vulnerable to immediate process crash.

A flaw was found in adm-zip. A remote attacker can exploit this vulnerability by providing a specially crafted ZIP file. The file's header can be manipulated to declare an extremely large uncompressed size, causing the application to allocate an excessive amount of memory. This excessive memory allocation can lead to an immediate process crash, resulting in a Denial of Service (DoS) for any application processing untrusted ZIP files with adm-zip.

A denial of service flaw exists in adm-zip, affecting applications that process untrusted ZIP archives. A specially crafted ZIP file with a manipulated uncompressed size header can lead to excessive memory allocation, causing an immediate process crash. This vulnerability can be exploited remotely without authentication, as the memory allocation occurs before CRC validation. Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. Red Hat Advanced Cluster Management for Kubernetes 2 Under investigation rhacm2/volsync-operator-bundle Red Hat Advanced Cluster Management for Kubernetes 2 Under investigation rhacm2/volsync-rhel9 Red Hat Build of Podman Desktop Under investigation rh-podman-desktop.git Red Hat Developer Hub Fix deferred rhdh/rhdh-hub-rhel9 Red Hat Enterprise Linux 8 Fix deferred dotnet5.0-build-reference-packages Red Hat Enterprise Linux 8 Fix deferred mozjs60 Red Hat Enterprise Linux 9 Fix deferred gjs Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-dashboard-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mlflow-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-automl-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-autorag-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-eval-hub-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-gen-ai-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-maas-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-mlflow-rhel9 Red Hat OpenShift AI (RHOAI) Fix deferred rhoai/odh-mod-arch-model-registry-rhel9 Red Hat OpenShift Container Platform 4 Not affected openshift4/ose-console Red Hat OpenShift Container Platform 4 Not affected openshift4/ose-monitoring-plugin-rhel9 Self-service automation portal 2 Fix deferred ansible-automation-platform/automation-portal https://www.cve.org/CVERecord?id=CVE-2026-39244 https://nvd.nist.gov/vuln/detail/CVE-2026-39244 https://github.com/cthackers/adm-zip https://github.com/cthackers/adm-zip/issues/568 https://www.npmjs.com/package/adm-zip