---
id: CVE-2026-70640
title: >-
  llama.cpp builds b1886 through b7445 contain a race condition use-after-free
  vulnerability in the LLaMA-Android JNI wrapper where bench_1model() and
  free_1context() lack synchronization, allowing Thread A to operate on freed
  memory while…
summary: >-
  llama.cpp builds b1886 through b7445 contain a race condition use-after-free
  vulnerability in the LLaMA-Android JNI wrapper where bench_1model() and
  free_1context() lack synchronization, allowing Thread A to operate on freed
  memory while…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-362
  - CWE-476
vendor: ggml
product: llama.cpp
affected:
  - 'llama.cpp >= b1886, <= b7445'
published: '2026-08-06'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T18:10:49.043'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70640'
references:
  - url: 'https://github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/ggml-org/llama.cpp/commit/5c0d18881e0e9794c96b2602736b758bac9d9388
    label: disclosure@vulncheck.com
  - url: 'https://github.com/ggml-org/llama.cpp/releases/tag/b7446'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/llama-cpp-b1886-b7445-race-condition-use-after-free-via-llama-android-cpp
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00185
epssPercentile: 0.08389
ingestedAt: '2026-09-21T18:50:57.547Z'
---

## Overview

llama.cpp builds b1886 through b7445 contain a race condition use-after-free vulnerability in the LLaMA-Android JNI wrapper where bench_1model() and free_1context() lack synchronization, allowing Thread A to operate on freed memory while Thread B concurrently frees the llama_context. Attackers can exploit this by performing heap spray with attacker-controlled data containing a fake vtable to hijack the vtable pointer at offset +0x30, causing llama_batch_allocr::clear() to dereference arbitrary memory and achieve remote code execution.

## Affected

- `llama.cpp >= b1886, <= b7445`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.