What is CVE-2026-16729?

CVE-2026-16729 is a medium-severity vulnerability in Undici, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 4.8/10. Published 2026-07-29.

How severe is CVE-2026-16729?

Medium severity. CVSS v3 base score is 4.8 out of 10.

Vulnerability in Undici

CVE-2026-16729

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 arr…

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Undici — versions 0, 6.28.0, 7.0.0

Weakness classification (CWE)

CWE-74 — Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection)

References

ce714d77-add3-4f53-aff5-83d477b104bb
ce714d77-add3-4f53-aff5-83d477b104bb

Frequently asked questions

What is CVE-2026-16729?: CVE-2026-16729 is a medium-severity vulnerability in Undici, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 4.8/10. Published 2026-07-29.
How severe is CVE-2026-16729?: Medium severity. CVSS v3 base score is 4.8 out of 10.