# CVE-2025-49847: llama.cpp: llama.cpp is an inference of several LLM models in C/C++

CVE-2025-49847 is fixed in llama.cpp on 1 platform by DEBIAN-CVE-2025-49847 (version 5713+dfsg-1), released June 17, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2025-49847
- Priority: High
- CVSS: 8.8 (high)
- EPSS: 0.0052
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 17, 2025

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | llama.cpp Debian 14 | 5713+dfsg-1 | [DEBIAN-CVE-2025-49847](https://patchblox.com/security/data/fix/linux/debian-cve-2025-49847.md) | Jun 17, 2025 |

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