216.73.216.6

CVE-2026-11525

· Published 17/06/2026 20:17 · Author: The MITRE Corporation

Labels: CVE-2026-11525 2026-06-17CVE-2026-11525CWE-183ce714d77-add3-4f53-aff5-83d477b104bb

Essential information

Published
17/06/2026 20:17
Modified
Author
The MITRE Corporation
Creator
The MITRE Corporation
CVSS
3.7 LOW (v3.1)
CISA KEV
No
CWE
CWE-183
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS metrics

Description

Impact: When undici parses a Set-Cookie header, it accepts any SameSite attribute value that contains Strict, Lax, or None as a substring, rather than the case-insensitive exact match specified by RFC 6265. Non-spec values are silently mapped to one of the three standard tokens. For example, SameSite=NoneOfYourBusiness is parsed as None (the most permissive setting), and SameSite=StrictLax is parsed as Lax (a downgrade from Strict). Affected applications are those that consume Set-Cookie headers from server responses (for example via undici's fetch or proxy code paths) and then forward or rely on the parsed sameSite attribute. A malicious or non-compliant server can coerce the consumer's view of a cookie's SameSite policy to a weaker value, silently degrading the SameSite enforcement the cookie is supposed to provide. This was introduced in undici 5.15.0 when the cookies feature was added. Patches: Upgrade to undici v6.26.0, v7.28.0 or v8.5.0. Workarounds: After parsing a Set-Cookie header, validate that the resulting sameSite attribute is one of 'Strict', 'Lax', or 'None' (exact, case-insensitive) before forwarding or relying on it.

NVD status

NVD
View on NVD