Off-by-one Error Affecting yauzl package, versions >=3.2.0 <3.2.1
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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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
CVE-2026-31988 (opens in a new tab)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;
}