GHSA-xjj6-f33q-929c: High severity npm/undici vulnerability

Published Oct 23, 2026
·
Updated

Impact

undici's fetch() crashes the Node.js process when a malicious server returns a response with more than five content codings and closes the connection before sending the body. undici rejects such responses (a content-encoding limit), but it created the internal response stream before that check and returned without attaching an error listener or aborting the request. The early close then surfaces a content-length mismatch on that orphaned internal stream, which Node.js treats as an unhandled error and terminates the process. A remote, unauthenticated server can trigger this with a single response, even when the application correctly catches the fetch() rejection. undici 6.x, 7.x, and 8.x are affected.

Patches

Upgrade to 6.29.1, 7.30.1, or 8.12.2. undici now validates the content-encoding chain before creating the internal body stream and aborts the response when the limit is exceeded, so no error can surface on an orphaned stream.

Workarounds

None.

Affected Software

3 affected componentsFixes available
npm/undici>=8.0.0<8.12.2
8.12.2
npm/undici>=7.18.0<7.30.1
7.30.1
npm/undici>=6.23.0<6.29.1
6.29.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade npm/undici to a version that resolves this vulnerability.

    Fixed in 8.12.2
  2. Upgrade

    Upgrade npm/undici to a version that resolves this vulnerability.

    Fixed in 7.30.1
  3. Upgrade

    Upgrade npm/undici to a version that resolves this vulnerability.

    Fixed in 6.29.1
  4. Upgrade

    Upgrade undici to a version that resolves this vulnerability.

    Fixed in 6.29.1
  5. Upgrade

    Upgrade undici to a version that resolves this vulnerability.

    Fixed in 7.30.1
  6. Upgrade

    Upgrade undici to a version that resolves this vulnerability.

    Fixed in 8.12.2

Event History

Oct 23, 2026
Advisory Published
via GitHub·10:14 PM
Data Sourced
via GitHub·10:14 PM
DescriptionSeverityWeaknessAffected Software

Contact

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