CVE-2026-1528
Undici: Malicious WebSocket 64-bit length overflows parser and crashes the client
7.5
HIGH
CVSS 3.1
EPSS 0.12%
Description
ImpactA server can reply with a WebSocket frame using the 64-bit length form and an extremely large length. undici's ByteParser overflows internal math, ends up in an invalid state, and throws a fatal TypeError that terminates the process. Patches Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.
How to fix CVE-2026-1528
To remediate CVE-2026-1528, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 6.24.0 or later
Is CVE-2026-1528 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- >= 6.0.0, < 6.24.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |