CVE-2026-19795
Qiskit SDK is vulnerable when deserializing QPY Files and may overflow the available stack space.
02 Description
Qiskit SDK is vulnerable when deserializing QPY Files and may overflow the available stack space.
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.29% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 22.1% of scored records. A rank, not a probability.
- NVD base score
- 6.2 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVD analysis status
- Awaiting Analysis. NVD last modified this record on 2026-09-08.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-09-03 19:56Z1 MO AGO
- Last updated
- 2026-09-04 20:05Z1 MO AGO
- Reserved
- 2026-08-13
- Assigning CNA
- ibm
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.2)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-502Deserialization of Untrusted DataBase
- Data version
- 5.2
- Document digest
- 71aa01ca9aa4996feb0abab6fd652dcb94633ddde46d60ab008ae7ce0edd6e10
05 Affected products
06 References
07 Remediation
Remediation/Fixes guidance: The issue is addressed in Qiskit versions v2.5.2. This version is patched to prevent the stack overflow by no longer evaluating the expression tree for ParameterExpression objects recursively. Product(s)Version(s) number and/or range Remediation/Fix/Instructions<Qiskit SDK - qiskit.qpy.load() function>v2.5.2 Upgrade to the patched versions: qiskit v2.5.2.