What is CVE-2026-22036?

CVE-2026-22036 is a medium-severity vulnerability in Node.js Undici, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.9/10. Published 2026-01-14.

How severe is CVE-2026-22036?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Resource exhaustion in Node.js Undici

CVE-2026-22036

Undici is an HTTP/1.1 client for Node.js. Prior to 7.18.0 and 6.23.0, the number of links in the decompression chain is unbounded and the default maxHeaderSize allows a malicious server to insert thousands compression steps leading to high CPU usage and excessive memory allocation. This vulnerability is fixed in 7.18.0 and 6.23.0.

Published 2026-01-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (37.8th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.000

Affected products

Node.js Undici — versions < 6.23.0, >= 7.0.0, < 7.18.2

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

github.com/nodejs/undici/security/advisories/GHSA-g9mf-h72j-4rw9 (Vendor Advisory)
github.com/nodejs/undici/commit/b04e3cbb569c1596f86c108e9b52c79d8475dcb3 (Patch)

Frequently asked questions

What is CVE-2026-22036?: CVE-2026-22036 is a medium-severity vulnerability in Node.js Undici, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.9/10. Published 2026-01-14.
How severe is CVE-2026-22036?: Medium severity. CVSS v3 base score is 5.9 out of 10.