GHSA-rfgv-xxqx-mfg5

Suggest an improvement
Source
https://github.com/advisories/GHSA-rfgv-xxqx-mfg5
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-rfgv-xxqx-mfg5/GHSA-rfgv-xxqx-mfg5.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-rfgv-xxqx-mfg5
Aliases
Published
2026-09-29T18:21:33Z
Modified
2026-09-29T18:30:41Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
undici vulnerable to Denial of Service via unrequested WebSocket subprotocol
Details

Impact

The undici WebSocket client throws an uncaught TypeError during the opening handshake when a server's 101 response includes a Sec-WebSocket-Protocol header that the client never requested. The throw occurs in a queueMicrotask callback with no surrounding try/catch, so it propagates as an uncaught exception and terminates the Node.js process. This is a remote, unauthenticated denial of service against any application that opens a WebSocket to an attacker controlled or compromised server, or over a plaintext ws:// connection subject to a machine-in-the-middle. It affects the default new WebSocket(url) usage, where no subprotocol is requested. Per RFC 6455 section 4.1, an unrequested subprotocol must fail the connection, not crash it.

All releases starting at undici 6.7.0 are affected.

Patches

Upgrade to undici 6.28.1, 7.29.1, or 8.10.2.

Workarounds

No workaround is available. The fix must be applied through an upgrade.

Database specific 
{
    "cwe_ids":  [
        "CWE-248",
        "CWE-252"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-09-29T18:21:33Z",
    "nvd_published_at":  "2026-09-04T18:17:51Z",
    "severity":  "HIGH"
}
References

Affected packages

npm / undici

Package

Name
undici
View open source insights on deps.dev
Purl
pkg:npm/undici

Affected ranges

Type
SEMVER
Events
Introduced
6.7.0
Fixed
6.28.1

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-rfgv-xxqx-mfg5/GHSA-rfgv-xxqx-mfg5.json"

npm / undici

Package

Name
undici
View open source insights on deps.dev
Purl
pkg:npm/undici

Affected ranges

Type
SEMVER
Events
Introduced
7.0.0
Fixed
7.29.1

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-rfgv-xxqx-mfg5/GHSA-rfgv-xxqx-mfg5.json"

npm / undici

Package

Name
undici
View open source insights on deps.dev
Purl
pkg:npm/undici

Affected ranges

Type
SEMVER
Events
Introduced
8.0.0
Fixed
8.10.2

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-rfgv-xxqx-mfg5/GHSA-rfgv-xxqx-mfg5.json"