Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-84947

CVE-2026-84947MEDIUM

undici vulnerable to response truncation via oversized chunked responses in the dump interceptor

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  L  N    5.3   .0020    8.5     —

AFFECTED
  Product  Versions  Fixed
  undici   7.1.0 –   7.29.1

TIMELINE
  Sep 2   Reserved by openjs
  Sep 4   Published (CNA: openjs)
  Sep 15  RESCORED — CVE-2026-84947 (undici). CVSS 3.7 → 5.3 (NVD).

CWE-20, CWE-248 · CNA: openjs · CVSS v3.1 · 2 references · NVD status: Analyzed

Description

undici's dump interceptor reads and discards a response body up to a configurable maximum size. When a response declares a Content-Length that exceeds the maximum, the interceptor aborts cleanly, but when a response has no Content-Length and is chunked, the interceptor instead signals completion early once the accumulated size reaches the maximum, without pausing or aborting the request. Because the underlying parser keeps delivering body bytes, a second completion signal fires and trips an internal assertion, which aborts the request and tears down the connection. The application is left observing a misleading successful status with an empty or truncated body while the connection has actually been disconnected. This affects undici versions from 7.1.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 2, 2026	Reserved	Reserved by openjs
September 4, 2026	Published	Published (CNA: openjs)
September 15, 2026	RESCORED	RESCORED — CVE-2026-84947 (undici). CVSS 3.7 → 5.3 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
undici	undici	—	7.1.0	7.29.1

Weaknesses

CWE-20 · CWE-248

References (2)

https://cna.openjsf.org/security-advisories.html [Third Party Advisory]
https://github.com/nodejs/undici/security/advisories/GHSA-2gqq-gqf2-x968 [Vendor Advisory]

Authoritative record: CVE-2026-84947 at cve.org

Vendors: undici

Weaknesses: CWE-20 · CWE-248

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-84947 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.