CVE-2026-1528
HIGH7.5EPSS 0.12%Undici: Malicious WebSocket 64-bit length overflows parser and crashes the client
Published: 3/13/2026Modified: 4/28/2026
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.
Affected packages (2)
- Debian/node-undicifrom 0
- npm/undici>= 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 |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-1528
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-1528
- PATCHhttps://github.com/nodejs/undici
- WEBhttps://cna.openjsf.org/security-advisories.html
- WEBhttps://github.com/nodejs/undici/security/advisories/GHSA-f269-vfmq-vjvj
- WEBhttps://hackerone.com/reports/3537648