Qiskit SDK C API may trigger an out of bounds write on accessing the unitary matrix with qk_circuit_inst_unitary().
Summary
| CVE | CVE-2026-116501 |
|---|---|
| State | PUBLISHED |
| Assigner | ibm |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-08 17:16:37 UTC |
| Updated | 2026-11-10 05:17:57 UTC |
| Description | IBM Qiskit SDK 2.4.0 through 2.6.1 could allow a local attacker to execute arbitrary code due to an out-of-bounds write caused by improper input validation when accessing a corrupted unitary matrix. |
Risk And Classification
Primary CVSS: v3.1 8.4 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.001660000 probability, percentile 0.058510000 (date 2026-11-09)
Problem Types: CWE-787 | CWE-787 CWE-787 Out-of-bounds Write
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8.4 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.4 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | IBM | Qiskit SDK | affected 2.4.0 2.6.1 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.ibm.com/support/pages/node/7295237 | [email protected] | www.ibm.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: The vulnerability was reported to IBM by Nathan Rebello. (en)
Additional Advisory Data
Solutions
CNA: Remediation/Fixes guidance: The issue is addressed in Qiskit versions v2.6.2. This version is patched to detect this situation and write out a sentinel value to identify the instruction is in an inconsistent state. Product(s)Version(s) number and/or range Remediation/Fix/Instructions< Qiskit SDK https://github.com/qiskit/qiskit - qk_circuit_inst_unitary() function>v2.6.2 Upgrade to the patched versions: qiskit v2.6.2.
Workarounds
CNA: Workarounds/Mitigation guidance: None