{"cve":"CVE-2026-39244","nvd":{"published":"2026-07-10T17:16:57.123","modified":"2026-07-10T19:17:23.250","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400"],"references":["https://github.com/cthackers/adm-zip","https://github.com/cthackers/adm-zip/issues/568","https://www.npmjs.com/package/adm-zip","https://github.com/cthackers/adm-zip/issues/568"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:44:02.134301115+00:00"},"epss":{"cve":"CVE-2026-39244","score":0.00841,"percentile":0.57895,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-xcpc-8h2w-3j85","url":"https://osv.dev/vulnerability/GHSA-xcpc-8h2w-3j85","summary":"adm-zip: Crafted ZIP file triggers 4GB memory allocation","modified":"2026-09-10T03:51:12.573706300Z","packages":[{"ecosystem":"npm","name":"adm-zip","purl":"pkg:npm/adm-zip","ranges":["<0.6.0"],"fixed":["0.6.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}