GitHub Advisoryadvisory · npm
GHSA-g9mf-h72j-4rw9 Undici has an unbounded decompression chain in HTTP responses on Node.js Fetch API via Content-Encoding leads to resource exhaustion
MEDIUM
Official page ↗
- Aliases
- CVE-2026-22036
- Ecosystem
- npm
- Packages
- undici
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-770
- Reviewed
- 2026-01-14
Affected packages
• npm undici: >= 7.0.0, < 7.18.2 → fixed in 7.18.2
• npm undici: < 6.23.0 → fixed in 6.23.0
Description
Impact
The `fetch()` API supports chained HTTP encoding algorithms for response content according to RFC 9110 (e.g., Content-Encoding: gzip, br). This is also supported by the undici decompress interceptor.
However, 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.
Patches
Upgrade to 7.18.2 or 6.23.0.
Workarounds
It is possible to apply an undici interceptor and filter long `Content-Encoding` sequences manually.
References
• https://hackerone.com/reports/3456148
• https://github.com/advisories/GHSA-gm62-xv2j-4w53
• https://curl.se/docs/CVE-2022-32206.html
Related
Alias · CVE (1)
- CVE-2026-22036 Undici is an HTTP/1.1 client for Node.js. vulnerability
Weakness · CWE (1)
- CWE-770 Allocation of Resources Without Limits or Throttling weakness