Off-by-one Error Affecting yauzl package, versions >=3.2.0 <3.2.1
Threat Intelligence
Exploit Maturity
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
Proof of Concept
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Test your applications- Snyk IDSNYK-JS-YAUZL-15467445
- published12 Mar 2026
- disclosed12 Mar 2026
- creditCodeAnt AI Code Reviewer
Introduced: 12 Mar 2026
NewCVE-2026-31988 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade yauzl to version 3.2.1 or higher.
Overview
Affected versions of this package are vulnerable to Off-by-one Error via the entry.getLastModDate() function. An attacker can cause the process or the Node.js server to crash by submitting a malicious zip file containing a malformed NTFS extra field.
PoC
// Direct demonstration of the buffer OOB read
const data = Buffer.alloc(4); // NTFS extra field with 4 bytes of data
let cursor = 4;
while (cursor < data.length + 4) { // cursor reaches 4 = data.length
const tag = data.readUInt16LE(cursor); // THROWS: offset 4 out of range [0, 2]
cursor += 2;
const size = data.readUInt16LE(cursor);
cursor += 2;
}