Skip to content
Heist/ feed
UnratedFix available

undici vulnerable to Denial of Service via WebSocketStream unclean close

Type: advisorySource: OSV1 source record

## Impact undici's `WebSocketStream` crashes the client process when a WebSocket connection is closed abruptly without a close handshake. On such an unclean close, the internal socket-close handler calls `abort()` on the writable stream even when the application holds a writer lock. Per the WHATWG Streams standard, aborting a locked stream returns a promise that rejects with a `TypeError`, and the handler discards that promise. The unobserved rejection surfaces as an `unhandledRejection` and, under Node.js's default behavior, terminates the process. A malicious or compromised WebSocket server can crash a client with a single connection teardown (a TCP reset, a proxy teardown, or a protocol-violating frame). Affected applications are those using the `WebSocketStream` API and writing through a writer, which is the standard way to write. All releases from undici 7.0.0 are affected. WebSocketStream was introduced in 7.0.0. ## Patches Upgrade to undici v7.29.1 or v8.10.2. ## Workarounds No workaround is available.

Announced Group revision 1
Original source ↗

GHSA-rx4f-c7p8-82vq

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:GHSA-rx4f-c7p8-82vq

undici

Source reference: /affected/0/package/name

Affected versions
Not stated in this record
Fixed versions
7.29.1

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

undici

Source reference: /affected/1/package/name

Affected versions
Not stated in this record
Fixed versions
8.10.2

Source reference: /affected/1/ranges

Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "SEMVER",
        "events": [
          {
            "introduced": "7.0.0"
          },
          {
            "fixed": "7.29.1"
          }
        ]
      }
    ],
    "package": {
      "name": "undici",
      "purl": "pkg:npm/undici",
      "ecosystem": "npm"
    },
    "database_specific": {
      "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-rx4f-c7p8-82vq/GHSA-rx4f-c7p8-82vq.json"
    }
  },
  {
    "ranges": [
      {
        "type": "SEMVER",
        "events": [
          {
            "introduced": "8.0.0"
          },
          {
            "fixed": "8.10.2"
          }
        ]
      }
    ],
    "package": {
      "name": "undici",
      "purl": "pkg:npm/undici",
      "ecosystem": "npm"
    },
    "database_specific": {
      "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-rx4f-c7p8-82vq/GHSA-rx4f-c7p8-82vq.json"
    }
  }
]
Related CVEs
CVE-2026-85014

Source reference: /aliases

Publisher severity

No explicit severity was provided.

Event
#29751 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement