# CVE-2026-87029: node-undici: undici is an HTTP client library for Node.js

CVE-2026-87029 is fixed in 11 products on 1 platform, first by DEBIAN-CVE-2026-87029, released November 1, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-87029
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0026
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 15, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-undici Debian 14 | 8.12.2+dfsg+~cs3.2.3-1 | [DEBIAN-CVE-2026-87029](https://patchblox.com/security/data/fix/linux/debian-cve-2026-87029.md) | Nov 1, 2026 |
| Linux | nodejs24 amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-debuginfo amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-debugsource amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-devel amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-docs amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-full-i18n amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-libs amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-libs-debuginfo amzn 2023 | 1:24.22.1-1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | nodejs24-npm amzn 2023 | 1:11.19.1-1.24.22.1.1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |
| Linux | v8-13.6-devel amzn 2023 | 3:13.6.233.17-1.24.22.1.1.amzn2023.0.1 | [ALAS2023-2026-3330](https://patchblox.com/security/data/fix/linux/alas2023-2026-3330.md) | Nov 7, 2026 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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