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.
https://lua-users.org/lists/lua-l/2022-02/msg00001.html
https://lua-users.org/lists/lua-l/2022-02/msg00070.html
https://lua-users.org/lists/lua-l/2022-04/msg00009.html
https://github.com/lua/lua/commit/1f3c6f4534c6411313361697d98d1145a1f030fa
Source: MITRE
Published: 2022-04-08
Updated: 2023-05-03
Type: CWE-125
Base Score: 6.4
Vector: AV:N/AC:L/Au:N/C:P/I:N/A:P
Impact Score: 4.9
Exploitability Score: 10
Severity: MEDIUM
Base Score: 9.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Impact Score: 5.2
Exploitability Score: 3.9
Severity: CRITICAL