Memory Allocation with Excessive Size Value Affecting fflate package, versions >=0.4.8
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-FFLATE-22392372
- published10 Nov 2026
- disclosed5 Nov 2026
- creditictrun
Introduced: 5 Nov 2026
NewCVE-2026-122146 (opens in a new tab)How to fix?
There is no fixed version for fflate.
Overview
fflate is a High performance (de)compression in an 8kB package
Affected versions of this package are vulnerable to Memory Allocation with Excessive Size Value via the unzipSync function in src/index.ts. An attacker can supply a crafted ZIP archive whose entry declares an extremely large uncompressed size, causing unzipSync to allocate an enormous output buffer and exhaust the application’s memory. The supported impact is memory exhaustion, which can make the application fail during extraction.