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OpenAdvisories
High · 7.5 CVE-2026-39244 EUVD-2026-42960GHSA-xcpc-8h2w-3j85

adm-zip: Crafted ZIP file triggers 4GB memory allocation

Published Jul 10, 2026 · Updated Jul 10, 2026 · Assigned by mitre

Description

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.

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Wolfi

ReleasePackageFixed inAdvisory
Wolfi rolling saf 1.7.0-r0 —
Wolfi rolling sqlpad 7.5.7-r29 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm adm-zip < 0.6.0 0.6.0 GHSA-xcpc-8h2w-3j85

Advisories 1

References