Buffer overflow in Ggml-org Llama.cpp

CVE-2026-21869

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-negat…

Vulnerability class: Buffer Overflow

EPSS: 0.004 (61.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-21869?
CVE-2026-21869 is a high-severity vulnerability in Ggml-org Llama.cpp, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2026-01-07.
How severe is CVE-2026-21869?
High severity. CVSS v3 base score is 8.8 out of 10.