CVE-2026-116500

Unbound Recursion in QPY deserialization can lead to denial of service

Published Nov 8, 2026 CVSS 3.1 · 6.2 Medium EPSS < 1% KEV · Not listed
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.

Remediation

Vendor Solution

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.


Vendor Workaround

Workarounds/Mitigation guidance: None

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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.
Title Unbound Recursion in QPY deserialization can lead to denial of service
First Time appeared Ibm
Ibm qiskit Sdk
Weaknesses CWE-502
CPEs cpe:2.3:a:ibm:qiskit_sdk:2.4.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:qiskit_sdk:2.6.1:*:*:*:*:*:*:*
Vendors & Products Ibm
Ibm qiskit Sdk
References
Metrics cvssV3_1

{'score': 6.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ibm
Published
Updated
Nov 12, 2026, 8:07 PM
Reserved
Oct 26, 2026, 12:59 PM
Status
Awaiting Analysis
Published
Nov 8, 2026, 5:16 PM
Modified
Nov 12, 2026, 8:18 PM