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

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

- **Severity:** Medium 6.0 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Jan 2026
- **Updated:** 23 Jan 2026
- **Also known as:** GHSA-36j2-f825-qvgc

## 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 (UNIX Symbolic Link (Symlink) Following)

## Which versions are affected by CVE-2026-1386?

It affects 1 product.


Products: 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.

## Is CVE-2026-1386 being exploited?

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

## Other vulnerabilities in AWS Firecracker

- [CVE-2019-18960](https://insights.sbomify.com/CVE-2019-18960/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-5747](https://insights.sbomify.com/CVE-2026-5747/): Out-of-bounds Write in Firecracker virtio-pci Transport (high 8.7)
- [CVE-2020-27174](https://insights.sbomify.com/CVE-2020-27174/): Denial of service in n/a (high 7.5)
- [CVE-2020-16843](https://insights.sbomify.com/CVE-2020-16843/): Denial of service in n/a (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1386 and fix it if it is affected.

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

Affected product: AWS Firecracker. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-1386/ (Markdown: https://insights.sbomify.com/CVE-2026-1386/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1386
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1386
- OSV: https://osv.dev/vulnerability/CVE-2026-1386

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1386/
Summaries are generated and may contain mistakes; the official description above is the record.