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.
References (8)
Core 8
Core References
Permissions Required, VDB Entry vdb-entry
technical-description
https://vuldb.com/?id.344636
Permissions Required, VDB Entry signature
permissions-required
https://vuldb.com/?ctiid.344636
Permissions Required, VDB Entry third-party-advisory
https://vuldb.com/?submit.745263
Issue Tracking issue-tracking
https://github.com/ggml-org/llama.cpp/issues/18988
Issue Tracking issue-tracking
https://github.com/ggml-org/llama.cpp/issues/18988#event-4426704865
Various Sources exploit
https://github.com/user-attachments/files/24761101/poc.zip
Issue Tracking issue-tracking
patch
https://github.com/ggml-org/llama.cpp/pull/18993
Various Sources product
https://github.com/ggml-org/llama.cpp/
Scores
CVSS v3
3.3
EPSS
0.0002
EPSS Percentile
5.4%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-119
CWE-121
Status
published
Products (1)
ggml-org/llama.cpp
55abc39
Published
Feb 06, 2026
Tracked Since
Feb 18, 2026