body-parser vulnerable to Denial of Service via trailing bytes after a compressed request body

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

body-parser is body parsing middleware for Node.js and Express. In versions before 1.20.9 and in versions from 2.0.0 before 2.4.0, a single request can crash any application using body-parser with default options. When a request carries a Content-Encoding such as gzip, body-parser pipes it into a decompression stream and, after reading the body, leaves that stream 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 matching route is required because body parsing runs before routing, so any endpoint that parses a body is affected. The issue is fixed in body-parser 2.4.0 and 1.20.9, and users should upgrade to one of those versions or later. As a workaround, disable request-body inflation (set the body-parser inflate option to false) so encoded requests are rejected before any decompression stream is created.

Source published

22 Oct 2026 14:29:56 UTC

Source modified

22 Oct 2026 19:00:31 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

body-parser is body parsing middleware for Node.js and Express. In versions before 1.20.9 and in versions from 2.0.0 before 2.4.0, a single request can crash any application using body-parser with default options. When a request carries a Content-Encoding such as gzip, body-parser pipes it into a decompression stream and, after reading the body, leaves that stream 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 matching route is required because body parsing runs before routing, so any endpoint that parses a body is affected. The issue is fixed in body-parser 2.4.0 and 1.20.9, and users should upgrade to one of those versions or later. As a workaround, disable request-body inflation (set the body-parser inflate option to false) so encoded requests are rejected before any decompression stream is created.

Source published

22 Oct 2026 15:17:04 UTC

Source modified

22 Oct 2026 19:17:35 UTC

Observed here

25 Oct 2026 05:17:13 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

### Impact 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.

Source published

23 Oct 2026 20:53:11 UTC

Source modified

23 Oct 2026 21:00:06 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Publisher rating · HIGH