# CVE-2026-89021: MikroTik RouterOS Path Traversal via Container OCI/tar Image Extraction

> Attackers can achieve root-privileged file operations on MikroTik RouterOS by importing a crafted container image with malicious symlinks.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:H/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-46jg-fhwv-c6jp

## What is CVE-2026-89021?

CVE-2026-89021 is a medium-severity path traversal vulnerability in MikroTik RouterOS, published on 14 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

MikroTik RouterOS before 7.24.2 contains a path traversal vulnerability in the container package OCI/tar image extraction that allows attackers to write files outside the container root by supplying a crafted container image with symlinks pointing to arbitrary paths. Attackers can exploit unsanitized tar member path extraction during container import via /container/add to achieve root-privileged file creation, directory creation, file deletion via overlayfs whiteout, and hardlink creation on the persistent data partition without ever starting the container. The 7.23.x long-term branch does not contain this fix; the container binaries in container-7.23.3.npk and container-7.23.4.npk are byte-identical. The vendor has confirmed that the issue is not resolved in the long-term release and that the fix is carried forward only in the stable branch from 7.24.2 onward, with no backport to the long-term branch planned.

Weakness: CWE-59 (Improper Link Resolution Before File Access), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-89021?


## How do I fix CVE-2026-89021?

No fix has been published for CVE-2026-89021 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-89021 being exploited?

There is no known exploitation of CVE-2026-89021 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89021 and fix it if it is affected.

What it is: CVE-2026-89021 is a medium-severity path traversal vulnerability in MikroTik RouterOS, published on 14 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-89021 in the wild and no public exploit code.

Affected product: MikroTik RouterOS. 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-2026-89021/ (Markdown: https://insights.sbomify.com/CVE-2026-89021/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89021
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89021
- OSV: https://osv.dev/vulnerability/CVE-2026-89021

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89021/
Summaries are generated and may contain mistakes; the official description above is the record.