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FirecrackerApplication · Amazon

CVE-2026-1386

MEDIUM · 6.0 CVSS v3.1 Published 2026-01-23
Fix available
A fix is available. Upgrade to 1.13.2 or later.
See remediation →
62/100
Remediation priority · Elevated
Zero-click

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 · unedited
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.

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 confidence

A symlink following vulnerability in Firecracker's jailer component allows a local user with write access to pre-created jailer directories to overwrite arbitrary host files during the initialization copy phase at jailer startup, when the jailer runs with root privileges.

MitigationUpgrade Firecracker to version v1.13.2 or 1.14.1 or above to resolve the symlink vulnerability.

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
FirecrackerApplication
Affected:< 1.13.2= 1.14.0

CVSS 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
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Firecracker installation and version
    Run `firecracker --version` or check the firecracker binary version via `file $(which firecracker)` and compare against affected versions: < 1.13.2 or = 1.14.0
    Affected if Installed version is less than 1.13.2 or exactly 1.14.0
  2. Locate the jailer binary
    Search for the jailer binary in common paths such as `/usr/local/bin/jailer`, `/opt/firecracker/jailer`, or via `find / -name jailer -type f 2>/dev/null`
    Affected if Jailer binary exists and is in use on the system
  3. Determine if jailer runs with root privileges
    Review the startup configuration or script that launches the jailer (e.g., systemd service, launch script) and check if it runs as root or with uid 0
    Affected if Jailer is configured to run with root privileges (uid 0)
  4. Check for pre-created jailer directories
    Examine the jailer configuration for the `chroot_base` or `jail_dir` path, then list contents with `ls -la <jail_directory>`
    Affected if Pre-created jailer directories exist on the system
  5. Verify write permissions on jailer directories
    Run `ls -ld <jail_directory>` and check group/world write permissions; also check ownership of any files within those directories
    Affected if Non-root users have write access (write permission for group or others) to jailer directories or their contents

Environment is affected if Firecracker version is below 1.13.2 or exactly 1.14.0, the jailer component is in use, runs with root privileges, and pre-created jailer directories are writable by non-root users.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 1.13.2 or later
Fixed in 1.13.2
Interim mitigation

Upgrade Firecracker to version v1.13.2 or 1.14.1 or above to resolve the symlink vulnerability.

Recommended fix High confidence

v1.13.2 or 1.14.1 or above

  1. Download the fixed Firecracker release (v1.13.2 or 1.14.1 or above) from the official GitHub releases page
  2. Verify the integrity of the downloaded binary using the provided checksums/signatures
  3. Stop any running Firecracker microVMs
  4. Replace the existing Firecracker binary with the new fixed version
  5. Restart the Firecracker jailer with root privileges to verify the fix is applied
  6. Confirm the jailer initializes correctly without following malicious symlinks in the jailer directories

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firecracker Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-1386 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data