CVE-2026-1386 Arbitrary Host File Overwrite via Symlink in Firecracker Jailer

Medium 6.0 Published 23 Jan 2026 Updated 23 Jan 2026

Local attackers with write access to jailer directories can overwrite arbitrary host files via symlink attacks during startup if the jailer runs as root.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-1386?

CVE-2026-1386 is a medium-severity path traversal vulnerability in AWS Firecracker, published on 23 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A UNIX symbolic link following issue in the jailer component in Firecracker version v1.13.1 and earlier and 1.14.0 on Linux may allow a local host user with write access to the pre-created jailer directories to overwrite arbitrary host files via a symlink attack during the initialization copy at jailer startup, if the jailer is executed with root privileges.

To mitigate this issue, users should upgrade to version v1.13.2 or 1.14.1 or above.

Weakness: CWE-61

Which versions are affected by CVE-2026-1386?

It affects 1 product.

Products include Amazon Firecracker.

How do I fix CVE-2026-1386?

No fix has been published for CVE-2026-1386 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-1386 being exploited?

There is no known exploitation of CVE-2026-1386 in the wild and no public exploit code.

Sources

Also known as GHSA-36j2-f825-qvgc.