Description
undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| undici | undici | 6.25.0 – < 6.28.1, 7.28.0 – < 7.29.1, 8.1.0 – < 8.10.2 | 6.28.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | node-undici | 8.10.2+dfsg+~cs3.2.2-1 | — |
| Debian 13 | node-undici | No fix yet | — |
| Debian 12 | node-undici | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | node-undici | No fix yet | — |
| Ubuntu 26.04 LTS | node-undici | No fix yet | — |
| Ubuntu 24.04 LTS | node-undici | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | grafana12.4 | 12.4.9-0.6.hum1 | RHSA-2026:63782 |
| Red Hat Hardened Images 1 | nodejs24 +5 | 1:24.21.0-1.hum1 | RHSA-2026:71017 |
| Red Hat Hardened Images 1 | nodejs24-npm +1 | 2:11.19.0-1.24.21.0.1.hum1 | RHSA-2026:71017 |
| Red Hat Hardened Images 1 | nodejs26 +6 | 1:26.8.2-0.1.hum1 | RHSA-2026:66605 |
| Red Hat Hardened Images 1 | nodejs26-npm | 1:11.19.1-1.26.8.2.0.1.hum1 | RHSA-2026:66605 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | pi-coding-agent | 1.0.4-bp160.1.1 | openSUSE-SU-2026:22111-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | nodejs22 +4 | 1:22.23.2-1.amzn2023.0.3 | ALAS2023-2026-3123 |
| Amazon Linux 2023 | nodejs22-npm | 1:10.9.8-1.22.23.2.1.amzn2023.0.3 | ALAS2023-2026-3123 |
| Amazon Linux 2023 | nodejs24 +4 | 1:24.21.0-1.amzn2023.0.1 | ALAS2023-2026-3107 |
| Amazon Linux 2023 | nodejs24-npm | 1:11.19.0-1.24.21.0.1.amzn2023.0.1 | ALAS2023-2026-3107 |
| Amazon Linux 2023 | v8-12.4-devel | 3:12.4.254.21-1.22.23.2.1.amzn2023.0.3 | ALAS2023-2026-3123 |
| Amazon Linux 2023 | v8-13.6-devel | 3:13.6.233.17-1.24.21.0.1.amzn2023.0.1 | ALAS2023-2026-3107 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | code-server | 4.139.1-r2 | — |
| Wolfi rolling | lerna | 10.0.1-r11 | — |
| Wolfi rolling | prism | 5.16.0-r14 | — |
| Wolfi rolling | pulumi-language-nodejs | 3.265.0-r3 | — |
| Wolfi rolling | renovate | 44.118.2-r0 | — |
| Wolfi rolling | vitess-24 | 24.0.3-r9 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | undici | >= 6.25.0, < 6.28.1 | 6.28.1 | GHSA-3wwx-pv8p-q78v |
| npm | undici | >= 7.28.0, < 7.29.1 | 7.29.1 | GHSA-3wwx-pv8p-q78v |
| npm | undici | >= 8.1.0, < 8.10.2 | 8.10.2 | GHSA-3wwx-pv8p-q78v |
Advisories 7
- RHSA-2026:71017 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- RHSA-2026:66605 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- WID-SEC-2026-3596 IBM App Connect Enterprise: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026
- RHSA-2026:63782 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 20, 2026
- openSUSE-SU-2026:22111-1 Security update for pi-coding-agent SUSE / openSUSE Security Updates · Oct 19, 2026
- ALAS2023-2026-3107 Important: nodejs24 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026
- ALAS2023-2026-3123 Important: nodejs22 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026