nodejs/undici · Security

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

GHSA ID
GHSA-2gqq-gqf2-x968
CVE ID
CVE-2026-84947
Severity
low
Published
Updated
CVSS
3.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v3
3.7 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Description

Impact

undici's interceptors.dump() reads and discards response bodies up to a configurable maxSize. When a response declares a Content-Length that exceeds maxSize, the request is aborted cleanly. When a response is sent chunked (no Content-Length) and its body exceeds maxSize, it is not aborted: the interceptor ends the response early once the accumulated size reaches maxSize, and continued delivery from the parser triggers an internal assertion that is caught and turned into a request abort and connection tear-down. The application observes a misleading 200 with an empty or truncated body while the connection is disconnected. Any application using the dump interceptor against untrusted or misbehaving upstreams is affected.

Patches

Upgrade to 7.29.1 or 8.10.2. The dump interceptor now enforces maxSize on both the declared and the received body size, aborting the request with a RequestAbortedError instead of returning a truncated response.

Workarounds

None. Avoid using interceptors.dump() with untrusted upstreams until upgraded.

CWEs

References