High (8.1) in facebook hhvm. EPSS 1.1% chance of exploitation in the next 30 days.
Insufficient boundary checks when decoding JSON in JSON_parser allows read access to out of bounds memory, potentially leading to information leak and DOS. This issue affects HHVM 4.45.0, 4.44.0, 4.43.0, 4.42.0, 4.41.0, 4.40.0, 4.39.0, versions between 4.33.0 and 4.38.0 (inclusive), versions between 4.9.0 and 4.32.0 (inclusive), and versions prior to 4.8.7.
Severity
CVSS 3.1
8.1 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H
EPSS
1.1% chance of exploitation in the next 30 days; higher than 65% of CVEs (scores of 2026-10-31)