CVE-2026-116500: medium-severity vulnerability in IBM Qiskit SDK
Unbound Recursion in QPY deserialization can lead to denial of service
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
10Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.2
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.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
IBM · Qiskit SDKRelated CVEs — IBM Qiskit SDK
In the same product, most dangerous first.
CVE-2025-2000CRITICALQiskit SDK code executionEPSS 0.8%CVE-2025-1403HIGHQiskit SDK denial of serviceEPSS 0.7%CVE-2026-19795MEDIUMQiskit SDK is vulnerable when deserializing QPY Files and may overflow the available stack space.EPSS 0.3%CVE-2026-4870HIGHQiskit SDK is vulnerable to specific functions may recurse too deeply and overflow the available stack space, when encountering certain classical expressions.EPSS 0.3%CVE-2026-116501HIGHQiskit SDK C API may trigger an out of bounds write on accessing the unitary matrix with qk_circuit_inst_unitary().EPSS —CVE-2026-116499HIGHArbitrary Code Execution in Qiskit SDK QPY DeserializationEPSS —