---
id: "CVE-2026-123203"
kind: "vulnerability"
aliases: ["CVE-2026-123203"]
title: "NEURON CoreNEURON: stack overflow from crafted model files crashes the process"
severity: "medium"
cvss: 6.9
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["coreneuron", "neuron", "nrniv-core", "package", "scientific-computing"]
not_affected_if: ["trusted-models-only"]
published_at: "2026-11-05T19:17:19+00:00"
first_seen_at: "2026-11-05T19:40:36+00:00"
updated_at: "2026-11-05T19:43:12+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123203", "first_seen_at": "2026-11-05T19:40:36+00:00"}]
exploit_sources: []
---

# NEURON CoreNEURON: stack overflow from crafted model files crashes the process

NEURON (CoreNEURON) through 9.0.2 has a stack buffer overflow when it loads over-long tokens from crafted model dataset files such as bbcore_mech.dat, globals.dat, or files.dat. An attacker who supplies such a dataset can corrupt stack memory and crash the nrniv-core process.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed NEURON or CoreNEURON version against the product range (through 9.0.2 is affected).
- Look for model datasets loaded by `nrniv-core` that come from untrusted sources.

## Timeline

- 2026-11-05T19:40:36+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123203

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/neuron-through-9.0.2-stack-based-buffer-overflow-via-coreneuron-dataset-tokens
- [fix] Patch: github.com https://github.com/neuronsimulator/nrn/commit/6e5a6578a3503c44ee0f19593e7ffb19812ef0e1

## From the sources

NEURON (CoreNEURON) through 9.0.2 contains a stack buffer overflow vulnerability that allows attackers to corrupt stack memory by supplying over-long tokens in a crafted model dataset. Attackers can place oversized version or mechanism-name tokens in bbcore_mech.dat, globals.dat, or files.dat loaded by nrniv-core to crash the process.

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