CVE-2026-21869
Severity CVSS v4.0:
Pending analysis
Type:
CWE-787
Out-of-bounds Write
Publication date:
08/01/2026
Last modified:
08/01/2026
Description
llama.cpp is an inference of several LLM models in C/C++. In commits 55d4206c8 and prior, the n_discard parameter is parsed directly from JSON input in the llama.cpp server's completion endpoints without validation to ensure it's non-negative. When a negative value is supplied and the context fills up, llama_memory_seq_rm/add receives a reversed range and negative offset, causing out-of-bounds memory writes in the token evaluation loop. This deterministic memory corruption can crash the process or enable remote code execution (RCE). There is no fix at the time of publication.
Impact
Base Score 3.x
8.80
Severity 3.x
HIGH