CVE-2026-84947CWE-20CWE-248

CVE-2026-84947

Low · published September 4, 2026

CVSS v3.1
3.7
EPSS
0%
Percentile
9.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
3.7 · LOW
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00195 · 9.3th percentile
Weaknesses
CWE-20 · Improper Input Validation; CWE-248 · Uncaught Exception
Published
2026-09-04T21:17Z
References (2)
EPSS history
Timeline
  • 06 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 04 SEP 16:53Z
    undici vulnerable to response truncation via oversized chunked responses in the dump interceptor
    cvelistv5