| Name | CVE-2026-12151 |
| Description | Impact: The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service. Affected applications are those using the undici WebSocket client (new WebSocket(...)) or the WebSocketStream API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. All releases starting at undici 6.17.0 are affected. Patches: Upgrade to undici >= 6.26.0, >= 7.28.0, or >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1140363 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| node-undici (PTS) | bookworm | 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 | vulnerable |
| bookworm (security) | 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 | vulnerable |
| trixie | 7.3.0+dfsg1+~cs24.12.11-1 | vulnerable |
| forky | 8.5.0+dfsg+~cs3.2.0-3 | fixed |
| sid | 8.9.0+dfsg+~cs3.2.0-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| node-undici | source | (unstable) | 8.5.0+dfsg+~cs3.2.0-1 | | | 1140363 |
Notes
[trixie] - node-undici <no-dsa> (Minor issue)
[bookworm] - node-undici <postponed> (Minor issue; requires connecting to an attacker-controlled WebSocket endpoint, and the WebSocket API is experimental in 5.15.0)
https://github.com/nodejs/undici/security/advisories/GHSA-vxpw-j846-p89q