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

Severity: medium (CVSS 6.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-14 · updated 2026-09-24
Weakness: CWE-22

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.

Affected products

MikroTik RouterOS: before 7.24.2 — fixed in 7.24.2

How to fix

Upgrade to a fixed version: MikroTik RouterOS 7.24.2. Check the vendor advisory for mitigations.

References

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