Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nodejs | Undici | < 6.28.0 |
Related Weaknesses (CWE)
References
- https://cna.openjsf.org/security-advisories.htmlVendor Advisory
- https://github.com/nodejs/undici/security/advisories/GHSA-v3r7-h72x-cjcmVendor Advisory
FAQ
What is CVE-2026-16729?
CVE-2026-16729 is a vulnerability with a CVSS score of 4.8 (MEDIUM). 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 sem...
How severe is CVE-2026-16729?
CVE-2026-16729 has been rated MEDIUM with a CVSS base score of 4.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-16729?
Check the references section above for vendor advisories and patch information. Affected products include: Nodejs Undici.