CVE-2026-123203: neuronsimulator NEURON

NEURON through 9.0.2 Stack-based Buffer Overflow via CoreNEURON dataset tokens

CVSS 6.9 Medium

Published by the CVE Program (CNA: VulnCheck) at 5 Nov 2026, 18:16 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
neuronsimulator	NEURON pkg:pypi/neuron	affected 9.0.2 and earlier custom Other versions: unaffected

Identifiers

CVE-2026-123203

CNA

VulnCheck

Weakness (CWE)

CWE-121

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
6.9	Medium	4.0	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N	CNA (VulnCheck)Used for this record
6.1	Medium	3.1	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H	CNA (VulnCheck)

CISA KEV Not listed.
EPSS No score.

Timeline

5 Nov 2026, 18:16 UTC Confirmed by the CVE List
5 Nov 2026, 18:19 UTC First seen by agentprime
5 Nov 2026, 19:17 UTC Confirmed by NVD

Sources

References from the CNA

github.com/neuronsimulator/nrn/pull/3932 issue-trackingpatch
github.com/neuronsimulator/nrn/commit/6e5a6578a3503c44ee0f19593e7ffb19812ef0e1 patch
github.com/neuronsimulator/nrn/blob/ba5783378c0aa1d9ac95b4454bea94b15c63f75d/src/coreneuron/io/mk_mech.cpp#L81-L96 technical-description
www.vulncheck.com/advisories/neuron-through-9.0.2-stack-based-buffer-overflow-via-coreneuron-dataset-tokens third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.