CVE-2026-109855

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Source
https://cve.org/CVERecord?id=CVE-2026-109855
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-109855.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-109855
Aliases
  • GHSA-qq8j-7v2v-3rwp
Downstream
DEBIAN (1)
RHSA (2)
Published
2026-10-15T08:12:51Z
Modified
2026-10-16T02:47:59Z
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 WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
Details

undici is an HTTP client library for Node.js. In versions 8.11.0 and 8.11.1, its experimental WebSocket client, which is enabled by default when HTTP/2 is allowed, mishandles a failed WebSocket handshake over HTTP/2: the request is already marked completed, so the abort becomes a no-op and the underlying HTTP/2 stream is left open with no error listener. When a malicious server then destroys the connection, the orphaned stream emits an unhandled error and the Node.js process exits. A remote, unauthenticated server can therefore crash any client that opens a WebSocket to it over HTTP/2, resulting in a denial of service. The issue is fixed in undici 8.11.2, and users should upgrade to 8.11.2 or later. As a workaround, set allowH2 to false to disable HTTP/2 for WebSocket connections, or avoid opening WebSocket connections to untrusted servers.

Database specific 
{
    "cna_assigner":  "openjs",
    "cwe_ids":  [
        "CWE-248",
        "CWE-754"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109855.json"
}
References

Affected packages

Git / github.com/nodejs/undici

Affected ranges

Type
GIT
Repo
https://github.com/nodejs/undici
Events
Introduced
6e48f4873a677ed6a13fa3e3571b032f00244bdf
Fixed
7e016ad7e5bd6540170069a9a28b1e633b29664f
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "8.11.0"
        },
        {
            "fixed":  "8.11.2"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Affected versions

v8.*
v8.11.0
v8.11.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-109855.json"