Cache Interceptor Vulnerability in Undici by Node.js
CVE-2026-84933

6.5MEDIUM

Key Information:

Vendor

Undici

Status
Undici
Vendor
CVE Published:
4 September 2026

What is CVE-2026-84933?

Undici's cache interceptor fails to properly manage the Set-Cookie response header. When operating in shared cache mode, it inappropriately stores responses containing this header, leading to potential leakage of user-specific cookies between different clients. This vulnerability allows cookies from one user to be served to another, compromising privacy and security. Affected users are advised to upgrade to undici versions 7.29.1 or 8.10.2 to mitigate this issue.

Affected Version(s)

undici 7.0.0 < 7.29.1

undici 8.0.0 < 8.10.2

undici 7.29.1

References

https://github.com/nodejs/undici/security/advisories/GHSA...
https://cna.openjsf.org/security-advisories.html

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
High
Integrity:
Low
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

mcollina
UlisesGascon
.