CVE-2026-43629 Details

A heap buffer overflow vulnerability has been identified in llama.cpp versions b4882 through b9058. The issue arises in the KV cache state restore process, where the state_read_data() function calculates the write size without proper overflow checks. This flaw allows attackers with write access to the slot_save_path directory to manipulate heap memory. By crafting malicious state files that exploit cell_count multiplication overflow or exceed tensor buffer allocations, attackers can write controlled bytes beyond buffer limits. This could lead to corruption of heap metadata, model weights, or even arbitrary code execution through function pointer overwrites.

Users can apply the available patch for this vulnerability, which is included in the 'llama.cpp Security Patches' repository. Instructions for applying the patch are provided in the repository.