CVE-2026-27940: high-severity vulnerability in ggml-org llama.cpp
llama.cpp has a Heap Buffer Overflow via Integer Overflow in `mem_size` Calculation — Bypass of CVE-2025-53630 Fix
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.2%
llama.cpp is an inference of several LLM models in C/C++. Prior to b8146, the gguf_init_from_file_impl() in gguf.cpp is vulnerable to an Integer overflow, leading to an undersized heap allocation. Using the subsequent fread() writes 528+ bytes of attacker-controlled data past the buffer boundary. This is a bypass of a similar bug in the same file - CVE-2025-53630, but the fix overlooked some areas. This vulnerability is fixed in b8146.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected products
ggml-org · llama.cppRelated CVEs — ggml-org llama.cpp
In the same product, most dangerous first.
CVE-2026-34159CRITICALllama.cpp: Unauthenticated RCE via GRAPH_COMPUTE buffer=0 bypass in llama.cpp RPC backendEPSS 1.6%CVE-2026-78148MEDIUMggml-org llama.cpp ggml-RPC Server ggml-rpc.cpp graph_compute null pointer dereferenceEPSS 0.7%CVE-2026-17501MEDIUMggml-org llama.cpp JSON-Schema-to-GBNF Conversion json-schema-to-grammar.cpp transform recursionEPSS 0.7%CVE-2026-17500MEDIUMggml-org llama.cpp json-schema-to-grammar.cpp _visit_pattern null pointer dereferenceEPSS 0.7%CVE-2026-86317MEDIUMggml-org llama.cpp RPC Server ggml-rpc.cpp deserialize_tensor assertionEPSS 0.7%CVE-2026-43629CRITICALllama.cpp b4882–b9058 Buffer Overflow in KV Cache State RestoreEPSS 0.7%