CVE-2026-34159

published 2026-04-01

CVE-2026-34159: llama.cpp is an inference of several LLM models in C/C++. Prior to version b8492, the RPC backend's deserialize_tensor() skips all bounds validation when a…

Priority P2 71 critical 9.8 CVSS 3.1

AV N AC L PR N UI N S U C H I H A H

llama.cpp is an inference of several LLM models in C/C++. Prior to version b8492, the RPC backend's deserialize_tensor() skips all bounds validation when a tensor's buffer field is 0. An unauthenticated attacker can read and write arbitrary process memory via crafted GRAPH_COMPUTE messages. Combined with pointer leaks from ALLOC_BUFFER/BUFFER_GET_BASE, this gives full ASLR bypass and remote code execution. No authentication required, just TCP access to the RPC server port. This issue has been patched in version b8492.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
debian	llama.cpp	< llama.cpp 8611+dfsg-1 (sid)	llama.cpp 8611+dfsg-1 (sid)
ggml-org	llama.cpp	< b8492	b8492
ggml	llama.cpp	< b8492	b8492

Detection & IOCs extracted from sources · hover to see the quote

command GRAPH_COMPUTE↗

command ALLOC_BUFFER↗

command BUFFER_GET_BASE↗

• → Monitor for unauthenticated TCP connections to the llama.cpp RPC server port; any external access should be treated as suspicious given no authentication is required to exploit this vulnerability. ↗
• → Detect crafted RPC messages targeting deserialize_tensor() where the tensor's buffer field is set to 0, which bypasses all bounds validation and enables arbitrary memory read/write. ↗
• → Flag GRAPH_COMPUTE RPC messages arriving from unauthenticated/external sources as potential exploitation attempts for arbitrary process memory access. ↗
• → Detect sequences of ALLOC_BUFFER and BUFFER_GET_BASE RPC calls from unauthenticated clients, which may indicate an attacker performing pointer leak reconnaissance for ASLR bypass prior to RCE. ↗

• · The llama.cpp RPC server requires no authentication by design (prior to patch b8492), meaning any network-level access to the RPC port is sufficient for exploitation. Restrict RPC server exposure to trusted networks or localhost only. ↗
• · Patch to llama.cpp version b8492 or later (Debian: 8611+dfsg-1) to remediate the missing bounds validation in deserialize_tensor(). ↗

CVSS provenance

nvd v3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

vendor_debian 9.8 CRITICAL

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