php_zip.c in the zip extension in PHP before 5.5.37, 5.6.x before 5.6.23, and 7.x before 7.0.8 improperly interacts with the unserialize implementation and garbage collection, which allows remote attackers to execute arbitrary code or cause a denial of service (use-after-free and application crash) via crafted serialized data containing a ZipArchive object.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
9.3% chance of exploitation in the next 30 days; higher than 95% of CVEs (scores of 2026-10-31)