What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-23 · updated 2026-06-17
• Weakness: CWE-61

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.

Affected products

• AWS Firecracker: before 1.13.2; 1.14.0, 1.14.0-dev — fixed in 1.13.2

How to fix

Upgrade to a fixed version: AWS Firecracker 1.13.2. Check the vendor advisory for mitigations.

References

• https://aws.amazon.com/security/security-bulletins/2026-003-AWS/
• https://github.com/firecracker-microvm/firecracker/releases/tag/v1.13.2
• https://github.com/firecracker-microvm/firecracker/releases/tag/v1.14.1
• https://github.com/firecracker-microvm/firecracker/security/advisories/GHSA-36j2-f825-qvgc

Get alerted when CVE-2026-1386 or the next vulnerability affects your stack