CVE-2026-70638 llama.cpp b1886–b7445 Integer Overflow via new_1batch() in llama-android.cpp
Integer overflow in llama.cpp Android JNI wrapper allows attackers to cause heap corruption and execute arbitrary code via crafted model files.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-70638?
CVE-2026-70638 is a high-severity vulnerability in ggml-org llama.cpp, published on 6 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
llama.cpp builds b1886 through b7445 contain an integer overflow vulnerability in the LLaMA-Android JNI wrapper where the new_1batch() function multiplies sizeof(llama_seq_id) by an attacker-controlled n_seq_max parameter without overflow validation, causing heap buffer allocation to wrap and allocate insufficient memory. Attackers can exploit this by providing a crafted n_seq_max value through a malicious model file or JNI call to trigger heap corruption and achieve denial of service or arbitrary code execution on Android applications using the LLaMA-Android binding.
Which versions are affected by CVE-2026-70638?
It affects 1 product.
Products include Ggml Llama.cpp.
How do I fix CVE-2026-70638?
Apply the vendor's patch.
Is CVE-2026-70638 being exploited?
There is no known exploitation of CVE-2026-70638 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in ggml-org llama.cpp
- CVE-2024-42479 llama.cpp allows write-what-where in rpc_server::set_tensor
- CVE-2026-34159 llama.cpp: Unauthenticated RCE via GRAPH_COMPUTE buffer=0 bypass in llama.cpp RPC backend
- CVE-2026-43629 llama.cpp b4882–b9058 Buffer Overflow in KV Cache State Restore
- CVE-2026-43631 llama.cpp b7492–b9060 Use-After-Free RCE via llama-server
- CVE-2026-43632 llama.cpp b7492–b9060 Use-After-Free in Tokenization Endpoints
Sources
Also known as DEBIAN-CVE-2026-70638, GHSA-p56f-gv6x-v6mg.