CVE-2026-21869
llama.cpp: llama.cpp: Remote code execution via invalid n_discard parameter in server endpoints
Severity by source
Trivy's own label is CRITICAL. Rated critical by NVD. Rated lower by Red Hat (high).
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.
Affected packages and fixed versions
| Source | Package | Fixed in |
|---|---|---|
| debian 14 | llama.cpp | 7593+dfsg-1 |
| rapidfort alpine 3.20 | llama.cpp | no fix listed |
| rapidfort alpine 3.21 | llama.cpp | no fix listed |
| rapidfort alpine 3.22 | llama.cpp | no fix listed |
| rapidfort alpine 3.23 | llama.cpp | no fix listed |
| rapidfort alpine 3.24 | llama.cpp | no fix listed |