undici

CVE-2026-22036

CVE-2026-22036 is a medium-severity allocation of resources without limits or throttling vulnerability in undici (npm), affecting versions >= 7.0.0, < 7.18.2. It is fixed in 7.18.2, 6.23.0.

Key facts
CVSS score
5.9
Medium
Attack vector
Network
Issuing authority
GitHub Advisory Database
Affected package
undici
Fixed in
7.18.2, 6.23.0
Disclosed
2026

Summary

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

Impact

What is allocation of resources without limits or throttling?

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

Severity and exposure

CVE-2026-22036 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.

A fixed version is available (7.18.2, 6.23.0). Upgrading removes the vulnerable code path.

Affected versions

npm

  • undici (>= 7.0.0, < 7.18.2)
  • undici (< 6.23.0)

Security releases

  • undici → 7.18.2 (npm)
  • undici → 6.23.0 (npm)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2026-22036 is reachable in your applications. Explore open-source security for your team.

See if CVE-2026-22036 is reachable in your applications. Get a demo

Remediation advice

Upgrade the following packages to resolve this vulnerability:

  • Upgrade undici to 7.18.2 or later
  • Upgrade undici to 6.23.0 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2026-22036

What is CVE-2026-22036?

CVE-2026-22036 is a medium-severity allocation of resources without limits or throttling vulnerability in undici (npm), affecting versions >= 7.0.0, < 7.18.2. It is fixed in 7.18.2, 6.23.0. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.

How severe is CVE-2026-22036?

CVE-2026-22036 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which versions of undici are affected by CVE-2026-22036?

undici (npm) versions >= 7.0.0, < 7.18.2 is affected.

Is there a fix for CVE-2026-22036?

Yes. CVE-2026-22036 is fixed in 7.18.2, 6.23.0. Upgrade to this version or later.

Is CVE-2026-22036 exploitable, and should I be worried?

Whether CVE-2026-22036 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2026-22036 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-22036?
  • Upgrade undici to 7.18.2 or later
  • Upgrade undici to 6.23.0 or later

Stop the waste.
Protect your environment with Kodem.