CVE-2026-87029
Public on 2026-10-15
Modified on 2026-10-16
Description
undici is an HTTP client library for Node.js. In versions 7.15.0 through 7.30.0 and 8.0.0 through 8.12.1, its decompress interceptor forwards decompressed response data to the downstream handler from zlib stream event callbacks without catching exceptions those callbacks may throw, and while undici's engine converts a synchronous throw from a downstream handler into a per-request failure, that protection is absent when the throw happens asynchronously from a zlib callback. As a result, a downstream handler that throws by design, such as the built-in dump interceptor which throws when a response exceeds its configured maximum size, escapes as an uncaught exception that terminates the Node.js process. A malicious or compromised HTTP server can crash any client that composes the decompress interceptor with such a handler by returning a small compressed body that decompresses to more than the configured limit, so only the decompressed size matters and the bytes on the wire stay tiny. The issue is fixed in undici 7.30.1 and 8.12.2, and users should upgrade to one of those versions or later. As a workaround, avoid composing the decompress interceptor with a response handler that throws during response processing until upgrading.
Severity
See what this means
CVSS v3 Base Score
See breakdown
Affected Packages
| Platform | Package | Release Date | Advisory | Status |
|---|---|---|---|---|
| Amazon Linux 2023 | nodejs | No Fix Planned | ||
| Amazon Linux 2023 | nodejs20 | No Fix Planned | ||
| Amazon Linux 2023 | nodejs22 | Not Affected | ||
| Amazon Linux 2023 | nodejs24 | Pending Fix | ||
| Amazon Linux 2027 Preview | nodejs24 | Pending Fix |
CVSS Scores
| Score Type | Score | Vector | |
|---|---|---|---|
| Amazon Linux | CVSSv3 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |