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OpenAdvisories
High · 8.6 CVE-2025-52566 EUVD-2025-19074

llama.cpp tokenizer signed vs. unsigned heap overflow

Published Jun 24, 2025 · Updated Jun 24, 2025 · Assigned by GitHub_M

Description

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

VendorProductAffectedFixed
ggml-org llama.cpp < b5721 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 llama.cpp 5760+dfsg-1 —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 llama.cpp No fix yet —
Ubuntu 26.04 LTS llama.cpp No fix yet —
Ubuntu 25.10 llama.cpp No fix yet —

References