undici vulnerable to cookie attribute injection via unsanitized domain and unparsed setCookie fields

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-16729
StatePUBLISHED
Assigneropenjs
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-29 17:16:51 UTC
Updated2026-07-29 19:16:45 UTC
Descriptionundici'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.

Risk And Classification

Primary CVSS: v3.1 4.8 MEDIUM from ce714d77-add3-4f53-aff5-83d477b104bb

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Problem Types: CWE-74 | CWE-74 CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

VersionSourceTypeScoreSeverityVector
3.1ce714d77-add3-4f53-aff5-83d477b104bbSecondary4.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
3.1CNACVSS4.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Undici Undici affected 6.28.0 semver Not specified
CNA Undici Undici unaffected 6.28.0 semver Not specified
CNA Undici Undici affected 7.0.0 7.29.0 semver Not specified
CNA Undici Undici unaffected 7.29.0 semver Not specified
CNA Undici Undici affected 8.0.0 8.9.0 semver Not specified
CNA Undici Undici unaffected 8.9.0 semver Not specified

References

ReferenceSourceLinkTags
github.com/nodejs/undici/security/advisories/GHSA-v3r7-h72x-cjcm ce714d77-add3-4f53-aff5-83d477b104bb github.com
cna.openjsf.org/security-advisories.html ce714d77-add3-4f53-aff5-83d477b104bb cna.openjsf.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Zelys-DFKH (en)

CNA: mcollina (en)

CNA: UlisesGascon (en)

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