CVE-2026-4870: IBM Qiskit SDK 0.43.0 through 2.5.0 could allow an attacker to trigger a segmentation fault leading to a denia

Routine

HIGH 7.5REMOTEUPGRADE

CVE-2026-4870 is a high-severity flaw (CVSS 7.5) affecting qiskit software development kit. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 81%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-06-12
Last modified	2026-10-25

Publisher (CNA): IBM Corporation · Vendor: ibm

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-12 21:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

ibm qiskit software development kit UPGRADE

Affected: >= 0.43.0 and < 1.4.6 · >= 2.0.0 and < 2.4.2

Fixed in: 1.4.6, 2.4.2

Safe to downgrade to: a release before 0.43.0

1. Check installed version

apt-cache policy qiskit-software-development-kit || rpm -q qiskit-software-development-kit || qiskit-software-development-kit --version

2. UPGRADE to 1.4.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade qiskit-software-development-kit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade qiskit-software-development-kit

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.43.0 (Debian / Ubuntu)

apt-cache madison qiskit-software-development-kit sudo apt install qiskit-software-development-kit=<VERSION_BEFORE_0.43.0> sudo apt-mark hold qiskit-software-development-kit

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list qiskit-software-development-kit sudo dnf downgrade qiskit-software-development-kit-<VERSION_BEFORE_0.43.0> sudo dnf versionlock add qiskit-software-development-kit

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-4870?

qiskit software development kit: upgrade to 1.4.6, 2.4.2. Exact commands for each OS are on this page.

Is CVE-2026-4870 being exploited?

CVE-2026-4870 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-4870 affect?

CVE-2026-4870 affects qiskit software development kit. Severity is high (CVSS 7.5). 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.

How urgent is CVE-2026-4870?

Priority 36/100. High severity; Remotely exploitable, no login, no user action

References

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