CVE-2026-70638

Summary

llama.cpp builds b1886 through b7445 contain an integer overflow vulnerability in the LLaMA-Android JNI wrapper where the new_1batch() function multiplies sizeof(llama_seq_id) by an attacker-controlled n_seq_max parameter without overflow validation, causing heap buffer allocation to wrap and allocate insufficient memory. Attackers can exploit this by providing a crafted n_seq_max value through a malicious model file or JNI call to trigger heap corruption and achieve denial of service or arbitrary code execution on Android applications using the LLaMA-Android binding.

• one-multiply-too-many-cve-2026-70638-llama-cpp-android-jni-integer-overflowPoC

  Reproduces the CVE-2026-70638 integer overflow in llama.cpp Android JNI with a safe arithmetic demo, malicious GGUF generator, and Frida hook for authorized security research.