# CVE-2026-122192: AWS Firecracker memory access in guest VM after snapshot restore

Source: https://junglewise.ai/threats/cve-2026-122192-guest-access-to-firecracker-process-memory-after-a-failed-memory  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-04. Updated: 2026-11-04  
License: CC BY 4.0 with a link back

CVE-2026-122192 · Severity: high · CVSS 7.5 · Published 2026-11-04

Firecracker is a virtualization engine that powers AWS Lambda and other serverless services. A vulnerability in versions 0.23.0 through 1.16.1 allows a root user inside a guest VM to read or modify the memory of the Firecracker process itself under certain host memory conditions, specifically when VMs are restored from snapshots. AWS Lambda and other AWS services are not affected, but third-party deployments of Firecracker should upgrade immediately.

Technologies: [Amazon AWS](https://junglewise.ai/threats/technologies/aws). Vendors: [Amazon](https://junglewise.ai/threats/vendors/amazon), [AWS](https://junglewise.ai/threats/vendors/aws).

## Quick answers

**Is CVE-2026-122192 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-122192 being exploited in the wild.

**How severe is CVE-2026-122192?** High severity, with a CVSS score of 7.5, published 4 November 2026.

**Which products and versions are affected?** AWS Firecracker v0.23.0 through v1.16.1.

**Is there a fix for CVE-2026-122192?** Yes: fixed in Firecracker v1.16.2, v1.17.0. Until then: If upgrading is not immediately possible, restore snapshots using the Uffd memory backend instead of the File backend. On kernels without Linux 6.12 overcommit handling, use heuristic overcommit (vm.overcommit_memory=0) and keep the maximum discard size no greater than total RAM plus swap, and ensure the memory cgroup OOM killer remains enabled. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-122192 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-122192?** Check whether you run Amazon AWS or AWS Firecracker at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Firecracker v1.16.2, v1.17.0

If upgrading is not immediately possible, restore snapshots using the Uffd memory backend instead of the File backend. On kernels without Linux 6.12 overcommit handling, use heuristic overcommit (vm.overcommit_memory=0) and keep the maximum discard size no greater than total RAM plus swap, and ensure the memory cgroup OOM killer remains enabled.

## Technical details

A memory safety issue in Firecracker's snapshot restore mechanism fails to properly discard memory pages when using the File memory backend with balloon or virtio-mem devices, allowing a privileged guest process to access host process memory. The vulnerability requires specific conditions: a snapshot restore operation combined with host memory pressure or overcommit scenarios. The fix is available in Firecracker v1.16.2 and v1.17.0.

## Affected products

- AWS Firecracker v0.23.0 through v1.16.1

## Timeline

- 2026-11-04: disclosed

## References

- [https://aws.amazon.com/security/security-bulletins/rss/2026-169-aws/](https://aws.amazon.com/security/security-bulletins/rss/2026-169-aws/)

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