GitHub Advisoryadvisory · npm
GHSA-2gqq-gqf2-x968 undici vulnerable to response truncation via oversized chunked responses in the dump interceptor
LOW
Official page ↗
- Aliases
- CVE-2026-84947
- Ecosystem
- npm
- Packages
- undici
- Severity
- Low
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weaknesses
- CWE-20, CWE-248
- Reviewed
- 2026-09-29
Affected packages
• npm undici: >= 7.1.0, < 7.29.1 → fixed in 7.29.1
• npm undici: >= 8.0.0, < 8.10.2 → fixed in 8.10.2
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.
Related
Alias · CVE (1)
- CVE-2026-84947 undici's dump interceptor reads and discards a response body up to a configurable maximum size. vulnerability
References
- https://github.com/nodejs/undici/security/advisories/GHSA-2gqq-gqf2-x968 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-84947 advisory
- https://github.com/nodejs/undici/commit/21693f406f0142f3504192e9f9b022dcf84782ae web
- https://github.com/nodejs/undici/commit/6d583124e7cf60b640097d64144ed633cc450584 web
- https://cna.openjsf.org/security-advisories.html web
- https://github.com/nodejs/undici package
- https://github.com/nodejs/undici/releases/tag/v7.29.1 web
- https://github.com/nodejs/undici/releases/tag/v8.10.2 web