Buffer overflow in Ggml-Org Llama.cpp

CVE-2026-2069

A flaw has been found in ggml-org llama.cpp up to 55abc39. Impacted is the function llama_grammar_advance_stack of the file llama.cpp/src/llama-grammar.cpp of the component GBNF Grammar Handler. This manipulation causes stack-based buffer overflow. The attack needs to be launched locally. The exploit has been published and may be used. Patch name: 18993. To fix this issue, it is recommended to deploy a patch.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (2.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-2069?
CVE-2026-2069 is a low-severity vulnerability in Ggml-Org Llama.cpp, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 3.3/10. Published 2026-02-06.
How severe is CVE-2026-2069?
Low severity. CVSS v3 base score is 3.3 out of 10.