What is the CVSS score of CVE-2026-4870?

CVE-2026-4870 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of IBM Qiskit SDK are affected by CVE-2026-4870?

IBM Qiskit SDK (versions 0.43.0-2.5.0) contains a high-severity denial-of-service vulnerability exploitable by remote unauthenticated attackers, directly threatening operational continuity for…. A patch is available.

How to fix or mitigate CVE-2026-4870?

Within 24 hours: Enumerate all systems and applications using IBM Qiskit SDK 0.43.0-2.5.0 via dependency manifests and package registries. Within 7 days: Deploy the patched IBM Qiskit SDK version released by vendor, validating compatibility with dependent quantum workloads in a staging environment before production rollout. Within 30 days: Confirm full remediation by verifying all vulnerable versions have been removed from development, testing, and production systems.

IBM Qiskit SDK CVE-2026-4870

EUVD-2026-36575 HIGH

Uncontrolled Recursion (CWE-674)

2026-06-12 ibm

Denial Of Service IBM Qiskit Sdk

7.5

CVSS 3.1 · Vendor: ibm

Severity by source

Vendor (ibm) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

vuln.today AI

7.5 HIGH

Parser crash is reachable over the network with no auth or interaction when Qiskit ingests untrusted input; impact is availability only, no confidentiality or integrity loss.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (ibm).

CVSS VectorVendor: ibm

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Jun 12, 2026 - 21:23 vuln.today

DescriptionCVE.org

IBM Qiskit SDK 0.43.0 through 2.5.0 could allow an attacker to trigger a segmentation fault leading to a denial of service due to uncontrolled recursion in the parser.

AnalysisAI

Denial of service in IBM Qiskit SDK versions 0.43.0 through 2.5.0 allows remote attackers to crash the parser via uncontrolled recursion, triggering a segmentation fault. The CVSS 7.5 score (AV:N/AC:L/PR:N/UI:N) reflects unauthenticated network-reachable exploitation with high availability impact, though no public exploit identified at time of analysis. Affects quantum-computing workloads that ingest untrusted Qiskit/OpenQASM input.

Technical ContextAI

Qiskit SDK is IBM's open-source Python framework for building, transpiling, and running quantum circuits, widely used to interact with IBM Quantum hardware and simulators. The flaw resides in the SDK's parser component, which recurses without bounds on attacker-controlled input - a classic CWE-674 (Uncontrolled Recursion) class issue that exhausts the stack and produces a SIGSEGV in the underlying CPython process. The CPE 'cpe:2.3:a:ibm:qiskit_sdk:*' confirms the application-level scope, meaning any service or notebook that parses Qiskit source (e.g., OpenQASM or serialized circuits) from a non-trusted source inherits the risk.

RemediationAI

Patch available per vendor advisory - upgrade Qiskit SDK to the fixed release identified in IBM's bulletin at https://www.ibm.com/support/pages/node/7276123 (exact fix version not enumerated in the provided intelligence, so confirm against that advisory before deploying). As compensating controls while patching, refuse to parse Qiskit/OpenQASM/QPY artifacts from untrusted sources, place parsing inside a sandboxed worker process with a Python recursion limit (sys.setrecursionlimit) and an OS-level stack/CPU rlimit so a crash kills only the worker, and add size and nesting-depth checks at the API boundary that accepts circuit submissions; the trade-off is that legitimate deeply-nested circuits may be rejected and worker restarts add latency.