CVE-2026-6878 is a vulnerability in ByteDance verl up to version 0.7.1 affecting the math_equal function in prime_math/grader.py. The flaw involves unsafe use of eval(), leading to a sandbox escape that allows arbitrary code execution. The vulnerability can be exploited remotely but requires high attack complexity and is considered difficult to exploit. Public exploit code is available. The vendor has not responded to disclosure requests and no patch is currently available.