What is CVE-2026-1526?

CVE-2026-1526 is a high-severity vulnerability in Undici, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 7.5/10. Published 2026-03-12.

How severe is CVE-2026-1526?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Undici

CVE-2026-1526

The undici WebSocket client is vulnerable to a denial-of-service attack via unbounded memory consumption during permessage-deflate decompression. When a WebSocket connection negotiates the permessage-deflate extension, the client decompres…

EPSS: 0.000 (6.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Undici — versions < 6.24.0; 7.0.0 < 7.24.0, 6.24.0: 7.24.0

Weakness classification (CWE)

CWE-409 — Improper Handling of Highly Compressed Data (Data Amplification)

References

github.com/nodejs/undici/security/advisories/GHSA-vrm6-8vpv-qv8q
hackerone.com/reports/3481206
cna.openjsf.org/security-advisories.html
datatracker.ietf.org/doc/html/rfc7692

Frequently asked questions

What is CVE-2026-1526?: CVE-2026-1526 is a high-severity vulnerability in Undici, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 7.5/10. Published 2026-03-12.
How severe is CVE-2026-1526?: High severity. CVSS v3 base score is 7.5 out of 10.