Description
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.
Metrics
CVSS 3.1 3.3/10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| ggml-org | llama.cpp | 55abc39 |
References
- https://github.com/ggml-org/llama.cpp/
- https://github.com/ggml-org/llama.cpp/issues/18988
- https://github.com/ggml-org/llama.cpp/issues/18988#event-4426704865
- https://github.com/ggml-org/llama.cpp/pull/18993
- https://github.com/user-attachments/files/24761101/poc.zip
- https://vuldb.com/?ctiid.344636
- https://vuldb.com/?id.344636
- https://vuldb.com/?submit.745263
Timeline
- Published
- Feb 6, 2026
- Last modified
- Jun 17, 2026
- NVD status
- Deferred