CVE-2026-39244: adm-zip Crafted ZIP File Triggers 4GB Vulnerability

HIGH
Advisory Identifier: GHSA-xcpc-8h2w-3j85
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CVSS 7.5
CWE-789 CWE-400
Published
Advisory Summary

CVE-2026-39244 is a HIGH (CVSS 7.5) crafted zip file triggers 4gb vulnerability (CWE-789: Memory Allocation with Excessive Size Value) affecting adm-zip libraries in the npm ecosystem. The issue involves crafted zip file triggers 4gb memory allocation. Remediation is available by upgrading affected packages to version 0.6.0.

CVE-2026-39244 at a Glance

CVE Identifier CVE-2026-39244
GHSA Identifier GHSA-xcpc-8h2w-3j85
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-789: Memory Allocation with Excessive Size Value
Affected Product adm-zip
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-39244

To remediate this vulnerability, upgrade all affected adm-zip dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

adm-zip fixed: 0.6.0 
npm install adm-zip@0.6.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls adm-zip

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-39244, inspect your project dependencies using npm:

npm ls adm-zip

Analyze the terminal output to locate any version of adm-zip in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.6.0), your application is affected.

Note: The npm ls adm-zip command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-789: Memory Allocation with Excessive Size Value, where the product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. In adm-zip, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-39244 Affected adm-zip Versions

1 component(s)
Fixed Versions:
0.6.0
Product / Package Ecosystem Affected Versions Fixed Version
adm-zip
npm/adm-zip
npm
< 0.6.0
0.6.0

References

NVD — CVE-2026-39244 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39244
adm-zip Source Repository REPOSITORY
https://github.com/cthackers/adm-zip/issues/568
Security Fix Commit FIX COMMIT
https://github.com/cthackers/adm-zip/commit/2450dcf417aa29df49270237d18c5245794da3e2
adm-zip Source Repository REPOSITORY
https://github.com/cthackers/adm-zip
adm-zip Source Repository REPOSITORY
https://github.com/cthackers/adm-zip/releases

Frequently Asked Questions

What is CVE-2026-39244?
CVE-2026-39244 is a security vulnerability in adm-zip involving Crafted ZIP file triggers 4GB memory allocation under CWE-789: Memory Allocation with Excessive Size Value.
Which adm-zip versions are affected?
Affected versions include releases prior to 0.6.0 across affected packages: adm-zip.
What version fixes CVE-2026-39244?
Upgrading to 0.6.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is adm-zip affected?
Yes, adm-zip is affected in releases prior to 0.6.0. Upgrade your dependency to 0.6.0 or later.
What is the CVSS score of CVE-2026-39244?
CVE-2026-39244 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-39244?
CVE-2026-39244 is classified under CWE-789: Memory Allocation with Excessive Size Value (The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.).
How can I check npm dependencies for CVE-2026-39244?
Run the dependency tree command: 'npm ls adm-zip'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xcpc-8h2w-3j85",
  "modified" : "2026-07-17T21:50:08Z",
  "published" : "2026-07-10T18:32:19Z",
  "aliases" : [ "CVE-2026-39244" ],
  "summary" : "adm-zip: Crafted ZIP file triggers 4GB memory allocation",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "adm-zip"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.6.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-39244"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cthackers/adm-zip/issues/568"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cthackers/adm-zip/commit/2450dcf417aa29df49270237d18c5245794da3e2"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cthackers/adm-zip"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cthackers/adm-zip/releases"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-789" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-17T21:50:08Z",
    "nvd_published_at" : "2026-07-10T17:16:57Z"
  }
}