# CVE-2026-9679: node-undici: Impact: undici's cookie parser in parseSetCookie percent-decodes cookie values via qsUnescape, turning encoded sequen... CVE-2026-9679 is fixed in 22 products on 1 platform, first by SUSE-SU-2026:22368-1, released June 25, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-9679 - Priority: Routine - CVSS: 5.9 (medium) - EPSS: 0.0026 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 17, 2026 ## Description Impact: undici's cookie parser in parseSetCookie percent-decodes cookie values via qsUnescape, turning encoded sequences like %0D%0A, %00, %3B, and %3D into their literal byte equivalents. RFC 6265 ยง5.4 does not specify any decoding and browsers do not decode either. Applications that parse a Set-Cookie header and then forward the parsed value into a response header (proxies, middleware, SSR frameworks) become vulnerable to HTTP response header injection: an attacker-controlled upstream can inject arbitrary Set-Cookie, Location, or Cache-Control headers into the application's downstream response, enabling session fixation, open redirect, or cache poisoning. Affected applications are those that use undici's cookie parsing (parseSetCookie, parseCookie, getSetCookies) and forward the parsed cookie value into a response header. This was introduced in undici 7.0.0 via PR #3789. Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0. Workarounds: If upgrade is not immediately possible, do not forward values returned by parseSetCookie/parseCookie/getSetCookies directly into response headers; sanitize the value first to strip or reject CR, LF, NUL, ;, and = bytes. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | node-undici Debian 14 | 8.5.0+dfsg+~cs3.2.0-1 | [DEBIAN-CVE-2026-9679](https://patchblox.com/security/data/fix/linux/debian-cve-2026-9679.md) | Jun 28, 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 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22 opensuse-leap 16.0 | 22.23.0-160000.1.1 | [OPENSUSE-SU-2026:21058-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21058-1.md) | Jun 25, 2026 | | Linux | nodejs22 sles 15.6 | 22.23.0-150600.13.18.1 | [SUSE-SU-2026:2647-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2647-1.md) | Jun 26, 2026 | | Linux | nodejs22 sles 15.7 | 22.23.0-150700.3.12.1 | [SUSE-SU-2026:2695-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2695-1.md) | Jun 30, 2026 | | Linux | nodejs22 sles 16.0 | 22.23.0-160000.1.1 | [SUSE-SU-2026:22368-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22368-1.md) | Jun 25, 2026 | | Linux | nodejs22-debuginfo amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-debugsource amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-devel amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-docs amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-full-i18n amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-libs amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-libs-debuginfo amzn 2023 | 1:22.23.1-1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs22-npm amzn 2023 | 1:10.9.8-1.22.23.1.1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | nodejs24 amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24 opensuse-leap 16.0 | 24.18.0-160000.1.1 | [OPENSUSE-SU-2026:21236-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21236-1.md) | Jul 6, 2026 | | Linux | nodejs24 sles 15.7 | 24.17.0-150700.15.11.1 | [SUSE-SU-2026:2633-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2633-1.md) | Jun 25, 2026 | | Linux | nodejs24 sles 16.0 | 24.18.0-160000.1.1 | [SUSE-SU-2026:22565-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22565-1.md) | Jul 6, 2026 | | Linux | nodejs24-debuginfo amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-debugsource amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-devel amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-docs amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-full-i18n amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-libs amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-libs-debuginfo amzn 2023 | 1:24.18.0-1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | nodejs24-npm amzn 2023 | 1:11.16.0-1.24.18.0.1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | | Linux | v8-12.4-devel amzn 2023 | 3:12.4.254.21-1.22.23.1.1.amzn2023.0.1 | [ALAS2023-2026-1921](https://patchblox.com/security/data/fix/linux/alas2023-2026-1921.md) | Jul 6, 2026 | | Linux | v8-13.6-devel amzn 2023 | 3:13.6.233.17-1.24.18.0.1.amzn2023.0.1 | [ALAS2023-2026-1920](https://patchblox.com/security/data/fix/linux/alas2023-2026-1920.md) | Jul 6, 2026 | --- Data as of 2026-11-08T00:53:09Z UTC. 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