CVE-2026-31413

EIP tracks 2 public exploits for CVE-2026-31413. PoCs published by fearlessresponsesolution, Rat5ak.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-31413, a BPF verifier bug allowing container escape via arbitrary kernel memory read/write. The PoC includes multiple exploit tiers, from credential overwrite to kernel code injection, demonstrating full privilege escalation from CAP_BPF+CAP_PERFMON to root.

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR maybe_fork_scalars() is called for both BPF_AND and BPF_OR when the source operand is a constant. When dst has signed range [-1, 0], it forks the verifier state: the pushed path gets dst = 0, the current path gets dst = -1. For BPF_AND this is correct: 0 & K == 0. For BPF_OR this is wrong: 0 | K == K, not 0. The pushed path therefore tracks dst as 0 when the runtime value is K, producing an exploitable verifier/runtime divergence that allows out-of-bounds map access. Fix this by passing env->insn_idx (instead of env->insn_idx + 1) to push_stack(), so the pushed path re-executes the ALU instruction with dst = 0 and naturally computes the correct result for any opcode.