# CVE-2026-16729: node-undici: undici's setCookie function does not fully sanitize cookie attributes

CVE-2026-16729 is fixed in 22 products on 1 platform, first by DEBIAN-CVE-2026-16729, released August 5, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-16729
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0028
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 29, 2026

## Description

undici's setCookie function does not fully sanitize cookie attributes. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a domain value is not checked for semicolons and entries in the unparsed array are not sanitized, so attacker-influenced input can inject additional cookie attributes. For example, a domain value containing a semicolon can append attributes such as SameSite, and an unparsed entry can inject attributes such as HttpOnly, without the caller setting them. Applications that pass user-controlled input to these fields, such as multi-tenant or reverse-proxy servers that scope session cookies to a tenant-supplied domain, can have SameSite CSRF protections bypassed, or the Secure, HttpOnly, and SameSite attributes forced, stripped, or overridden. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-undici Debian 14 | 8.9.0+dfsg+~cs3.2.0-1 | [DEBIAN-CVE-2026-16729](https://patchblox.com/security/data/fix/linux/debian-cve-2026-16729.md) | Aug 5, 2026 |
| Linux | nodejs20 sles 15.6 | 20.20.2-150600.3.21.1 | [SUSE-SU-2026:3929-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3929-1.md) | Sep 3, 2026 |
| Linux | nodejs22 amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-debuginfo amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-debugsource amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-devel amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-docs amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-full-i18n amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-libs amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-libs-debuginfo amzn 2023 | 1:22.23.2-1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs22-npm amzn 2023 | 1:10.9.8-1.22.23.2.1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | nodejs24 amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-debuginfo amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-debugsource amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-devel amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-docs amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-full-i18n amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-libs amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-libs-debuginfo amzn 2023 | 1:24.18.1-1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | nodejs24-npm amzn 2023 | 1:11.16.0-1.24.18.1.1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |
| Linux | v8-12.4-devel amzn 2023 | 3:12.4.254.21-1.22.23.2.1.amzn2023.0.2 | [ALAS2023-2026-2060](https://patchblox.com/security/data/fix/linux/alas2023-2026-2060.md) | Aug 17, 2026 |
| Linux | v8-13.6-devel amzn 2023 | 3:13.6.233.17-1.24.18.1.1.amzn2023.0.2 | [ALAS2023-2026-2059](https://patchblox.com/security/data/fix/linux/alas2023-2026-2059.md) | Aug 17, 2026 |

---

Data as of 2026-11-08T13:06:02Z 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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