llama.cpp Vulnerable to Buffer Overflow via Malicious GGUF Model
At a glance
Severity
HIGH 8.8
EPSS
EPSS 0.52 % · percentile 44 (2026-10-28)
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Analyzed
Description
llama.cpp is an inference of several LLM models in C/C++. Prior to version b5662, an attacker‐supplied GGUF model vocabulary can trigger a buffer overflow in llama.cpp’s vocabulary‐loading code. Specifically, the helper _try_copy in llama.cpp/src/vocab.cpp: llama_vocab::impl::token_to_piece() casts a very large size_t token length into an int32_t, causing the length check (if (length < (int32_t)size)) to be bypassed. As a result, memcpy is still called with that oversized size, letting a malicious model overwrite memory beyond the intended buffer. This can lead to arbitrary memory corruption and potential code execution. This issue has been patched in version b5662.
