A single request can crash any application using body-parser with default options. When a request carries a Content-Encoding (for example gzip), body-parser pipes it into a decompression stream and, after reading the body, leaves that stream piped with no error listener. A payload of one valid compressed frame followed by trailing bytes decodes and the application responds normally, but the trailing bytes then reach the already-finished decoder, which emits an error that is re-thrown as an uncaught exception and terminates the process. No authentication or matching route is required, since parsing runs before routing.
// patches
Fixed in body-parser 2.4.0 and 1.20.9. Upgrade to one of these versions.
// workarounds
Pass inflate: false to the body-parser middleware if the application does not need to accept compressed request bodies. This rejects encoded requests before any decompression stream is created.
// cvss v3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Checked 2026-11-06 at 18:34 UTC. The most recent advisory here was published 2026-10-23. Updated continuously from NVD, GHSA, OSV and CNA feeds.