CVE-2026-81883: radare2: Out-of-bounds Read at the end of string in the LUA 5.3 bytecode

Severity: low (CVSS 3.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-09-22 · updated 2026-09-28
Weakness: CWE-125

Description

radare2 is a UNIX-like reverse engineering framework and command-line toolset. Prior to 6.2.0, radare2's Lua 5.3 bytecode function parser was vulnerable because the Lua 5.3 bytecode function parser read fixed function-metadata fields immediately after a function-name string without checking the remaining buffer length. The vulnerability is triggered by opening or inspecting a crafted Lua 5.3 bytecode file whose function-name string ends at the input-buffer boundary. The parser read two integers and three one-byte fields beyond the allocated input buffer. This can cause invalid parser results or process termination; no attacker-observable memory disclosure has been demonstrated. This issue is fixed in version 6.2.0.

Affected products

radareorg/radare2: before 6.2.0 — fixed in 6.2.0

How to fix

Upgrade to a fixed version: radareorg/radare2 6.2.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-81883 or the next vulnerability affects your stack