CVE-2026-19795 Qiskit SDK is vulnerable when deserializing QPY Files and may overflow the available stack space.
A local attacker can cause a denial of service via stack overflow when deserializing malicious QPY files in the Qiskit SDK.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-19795?
CVE-2026-19795 is a medium-severity unsafe deserialization vulnerability in IBM Qiskit SDK, published on 3 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Qiskit could allow a local attacker to cause a denial of service due to a stack overflow during deserialization of QPY payloads. A malicious QPY payload can trigger a segmentation fault, causing the application to crash when deserializing untrusted input.
Weakness: CWE-502
Which versions are affected by CVE-2026-19795?
How do I fix CVE-2026-19795?
No fix has been published for CVE-2026-19795 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-19795 being exploited?
There is no known exploitation of CVE-2026-19795 in the wild and no public exploit code.