Arbitrary Code Execution in Qiskit SDK QPY Deserialization
Affects Qiskit SDK 1.4.2 through 2.6.2 when a Python process loads QPY format versions below 13 with qiskit.qpy.load(). Fixed in 2.6.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 2.6.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affected Qiskit SDK versions 1.4.2 through 2.6.2. Occurs when deserialising QPY format versions below 13. The payload is processed by a Python process calling qiskit.qpy.load().
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 14/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
The Qiskit SDK, IBM's open-source quantum computing software, has a flaw in how it deserializes QPY data, which lets an attacker run arbitrary code. An attacker with local access can exploit it without logging in or needing any user action.
Read the original description
IBM Qiskit SDK 1.4.2 through 2.6.2 could allow a local attacker to execute arbitrary code due to deserialization of untrusted data.
cve.now Index
- Exploitation0/40No signal
- Exposure5/25Specific setups only
- Reach?/20Unknown. No tracked technology or package matched
- Severity9.4/10CVSS 8.4, total technical impact per CISA
- No patch0/5No signal
What would change the score
- Would score about 64 if added to CISA KEV
- Would score about 59 if CISA's SSVC rates exploitation active
- Would score about 24 if CISA's SSVC rates it automatable
What to do
Check whether your setup matches what the bug needs.
Affected Qiskit SDK versions 1.4.2 through 2.6.2. Occurs when deserialising QPY format versions below 13. The payload is processed by a Python process calling qiskit.qpy.load().Upgrade to a fixed version: 2.6.2.
Timeline
- CVE published
- First seen by cve.now1 day
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- IBM Qiskit SDK
From 1.4.2 · through 2.6.2
Evidence 1
- Patch
Corrections
None so far.
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Questions about CVE-2026-116499
Is CVE-2026-116499 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
Deserialising a QPY payload with format version below 13 through qiskit.qpy.load() could let a Python process execute arbitrary Python code contained in that payload.Source: ibm.com
Which versions are affected by CVE-2026-116499?
Qiskit SDK: from 1.4.2 through 2.6.2.Source: cve.now feed data
Am I affected, and how do I check?
Qiskit SDK versions 1.4.2 through 2.6.2 are affected, and only when QPY format versions below 13 are deserialised. Check the installed Qiskit SDK version and whether the code calls qiskit.qpy.load() on QPY files below format version 13.Source: ibm.com
How do I fix CVE-2026-116499?
Upgrade to Qiskit SDK 2.6.2, which addresses the issue.Source: ibm.com