Unbound Recursion in QPY deserialization can lead to denial of service
Summary
| CVE | CVE-2026-116500 |
|---|---|
| State | PUBLISHED |
| Assigner | ibm |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-08 17:16:37 UTC |
| Updated | 2026-11-08 17:16:37 UTC |
| Description | IBM Qiskit SDK 2.4.0 through 2.6.1 could allow a local attacker to cause a denial of service due to unbound recursion during deserialization of untrusted QPY payloads. |
Risk And Classification
Primary CVSS: v3.1 6.2 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.001620000 probability, percentile 0.054530000 (date 2026-11-09)
Problem Types: CWE-502 | CWE-502 CWE-502 Deserialization of Untrusted Data
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.2 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 6.2 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/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/7295235 | [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. Product(s)Version(s) number and/or range Remediation/Fix/Instructions< Qiskit SDK https://github.com/qiskit/qiskit - qiskit.qpy.load() function>v2.6.2 Upgrade to the patched versions: qiskit v2.6.2.
Workarounds
CNA: Workarounds/Mitigation guidance: None
There are currently no legacy QID mappings associated with this CVE.