Buffer overflow in Neuronsimulator Neuron
CVE-2026-123203
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.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/neuronsimulator/nrn/blob/ba5783378c0aa1d9ac95b4454bea94b15c63f75d/sr… (technical-description)
- github.com/neuronsimulator/nrn/commit/6e5a6578a3503c44ee0f19593e7ffb19812ef0e1 (patch)
- github.com/neuronsimulator/nrn/pull/3932 (issue-tracking, patch)
- VulnCheck Advisory: NEURON through 9.0.2 Stack-based Buffer Overflow via CoreNEURON dataset tokens (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123203?
- CVE-2026-123203 is a medium-severity vulnerability in Neuronsimulator Neuron, classified under Stack-based Buffer Overflow. CVSS score: 6.1/10. Published 2026-11-05.
- How severe is CVE-2026-123203?
- Medium severity. CVSS v3 base score is 6.1 out of 10.