CVE-2025-52566: Ggml Llama.cpp

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

llama.cpp is an inference of several LLM models in C/C++. Prior to version b5721, there is a signed vs. unsigned integer overflow in llama.cpp's tokenizer implementation (llama_vocab::tokenize) (src/llama-vocab.cpp:3036) resulting in unintended behavior in tokens copying size comparison. Allowing heap-overflowing llama.cpp inferencing engine with carefully manipulated text input during tokenization process. This issue has been patched in version b5721.

Affected products

• Ggml Llama.cpp: before b5721 (fixed in b5721)

Published 2025-06-24. Last modified 2026-06-17.