CVE-2026-2069CWE-119CWE-121

ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow

Medium · published February 6, 2026

CVSS v4.0
4.8
EPSS
0%
Percentile
3.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
4.8 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
EPSS
0.00145 · 3.4th percentile
Weaknesses
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer; CWE-121 · Stack-based Buffer Overflow
Published
2026-02-06T22:02Z
EPSS history
Timeline
  • 06 FEB 22:02Z
    ggml-org llama.cpp GBNF Grammar llama-grammar.cpp llama_grammar_advance_stack stack-based overflow
    cvelistv5