Numeric Truncation Error Affecting undici package, versions >=7.1.0 <7.29.1>=8.0.0 <8.10.2
Threat Intelligence
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-UNDICI-19635214
- published6 Sept 2026
- disclosed4 Sept 2026
- creditUnknown
Introduced: 4 Sep 2026
NewCVE-2026-84947 (opens in a new tab)How to fix?
Upgrade undici to version 7.29.1, 8.10.2 or higher.
Overview
undici is an An HTTP/1.1 client, written from scratch for Node.js
Affected versions of this package are vulnerable to Numeric Truncation Error in the interceptors.dump() interceptor, which, for a chunked response with no Content-Length, does not abort an oversized body but terminates after reaching maxSize and trips an internal assertion that is caught and converted into a request abort and connection tear-down. An attacker can cause the application to receive a misleading 200 response with a truncated or empty body, followed by a dropped connection, by returning from an upstream a chunked response without Content-Length that exceeds the dump limit. This requires the application to use the interceptors.dump() interceptor against an untrusted or misbehaving upstream.