Critical (9.1). EPSS 3.0% chance of exploitation in the next 30 days.
singlevar in lparser.c in Lua from (including) 5.4.0 up to (excluding) 5.4.4 lacks a certain luaK_exp2anyregup call, leading to a heap-based buffer over-read that might affect a system that compiles untrusted Lua code.
Severity
CVSS 3.1
9.1 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
3.0% chance of exploitation in the next 30 days; higher than 87% of CVEs (scores of 2026-10-31)