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

中 5.3CVE-2026-84947 · GHSA-2gqq-gqf2-x968 · 04/09/2026 公開 · 15/09/2026 更新

パッケージ	影響を受けるバージョン	修正済みバージョン
undici nodejs	`≥ 7.1.0, < 7.29.1≥ 8.0.0, < 8.10.2`	`7.29.18.10.2`
undici npm	`≥ 7.1.0, < 7.29.1≥ 8.0.0, < 8.10.2`	`7.29.18.10.2`

概要

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.

NVD の説明

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.