CVE-2026-43628 llama.cpp b3978–b9058 Integer Underflow via DRY Sampler
Unauthenticated attackers can cause denial of service or read memory via integer underflow in llama.cpp DRY sampler.
- 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
- None listed
What is CVE-2026-43628?
CVE-2026-43628 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 b3978 through b9058 contain an integer underflow and out-of-bounds read vulnerability in the DRY sampler that allows unauthenticated attackers to trigger a heap buffer underflow by sending a crafted HTTP request with dry_allowed_length set to INT32_MIN to the /v1/completions or /v1/chat/completions endpoints. Attackers can exploit this vulnerability to crash the server with SIGSEGV causing denial of service for all connected users, or corrupt token sampling probabilities by reading garbage values from memory before the allocated buffer.
Which versions are affected by CVE-2026-43628?
It affects 1 product.
Products include Ggml Llama.cpp.
How do I fix CVE-2026-43628?
No fix has been published for CVE-2026-43628 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-43628 being exploited?
There is no known exploitation of CVE-2026-43628 in the wild and no public exploit code.
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-2026-43628, GHSA-wvf4-v63v-mwm5, UBUNTU-CVE-2026-43628.