Permissive List of Allowed Inputs in undici - CVE-2026-11525
Published: June 17, 2026
Vulnerability identifier: #VU134752
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-11525
CWE-ID: CWE-183
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Node.js
Affected software:
undici
undici
Detailed vulnerability description
The vulnerability allows a remote attacker to weaken SameSite cookie policy enforcement.
The vulnerability exists due to permissive list of allowed inputs in the Set-Cookie header parser when parsing Set-Cookie headers from server responses. A remote attacker can send a specially crafted Set-Cookie header to weaken SameSite cookie policy enforcement.
The issue affects applications that forward or rely on the parsed sameSite attribute from server responses.
How to mitigate CVE-2026-11525
Install security update from vendor's website.