includes/core/is_user.php in NukeViet before 4.3.04 deserializes the untrusted nvloginhash cookie (i.e., the code relies on PHP's serialization format when JSON can be used to eliminate the risk).
Severity
CVSS 3.1
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
2.6% chance of exploitation in the next 30 days; higher than 85% of CVEs (scores of 2026-10-31)