CVE-2026-5747
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn out-of-bounds write issue in the virtio PCI transport in Firecracker 1.13.0 through 1.14.3 and 1.15.0 on x86_64 and aarch64 might allow a local guest user with root privileges to crash the Firecracker VMM process or potentially execute arbitrary code on the host via modification of virtio queue configuration registers after device activation. Achieving code execution on the host requires additional preconditions, such as the use of a custom guest kernel or specific snapshot configurations. To remediate this, users should upgrade to Firecracker 1.14.4 or 1.15.1 and later.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAn out-of-bounds write vulnerability in the virtio PCI transport of Firecracker 1.13.0 through 1.14.3 and 1.15.0 allows a local guest user with root privileges to modify virtio queue configuration registers after device activation, potentially crashing the VMM or executing arbitrary code on the host.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 1.13.0, <= 1.14.3= 1.15.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- High
- Privileges
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Firecracker version in useRun `firecracker --version` or check the firecracker binary version that launched the VM. If using a container or packaging, check the version of the firecracker package or image.Affected if The version is 1.13.0 through 1.14.3 inclusive, or exactly 1.15.0.
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Confirm virtio PCI transport is enabledReview the Firecracker VM configuration (the JSON boot source and device configs). Look for virtio-block, virtio-net, or other virtio devices defined in the network or block device configurations. These use the virtio PCI transport layer.Affected if Any virtio devices (virtio-net, virtio-block, virtio-vsock, etc.) are configured and active in the VM.
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Verify guest privilege modelDetermine whether untrusted or potentially malicious users have root-level access inside the guest VMs. Check guest user permissions and VM isolation policies.Affected if Guest VMs allow root or equivalent privileged access from untrusted users, making the attack vector viable.
You are affected if your Firecracker version is 1.13.0-1.14.3 or 1.15.0 AND you run any virtio devices with guest users who have root privileges.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Firecracker to version 1.14.4 or 1.15.1 and later to remediate this vulnerability.
Firecracker 1.14.4 or 1.15.1 and later
- 1. Identify all Firecracker instances running on the host that need to be upgraded.
- 2. Gracefully stop all running Firecracker virtual machines to ensure data integrity.
- 3. Upgrade the Firecracker binary to version 1.14.4 or 1.15.1 (or later) by replacing the existing binary.
- 4. Verify the new Firecracker version by running `firecracker --version`.
- 5. Restart the Firecracker virtual machines with the updated binary.
- 6. Confirm that the VMs are functioning correctly and the vulnerability is remediated.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-5747 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-5747 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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