CVE-2026-57155 OPNsense: Root RCE via Arbitrary File Write in GeoIP Alias Importer
A user with Firewall Alias Edit privilege can exploit path traversal in GeoIP import to write files as root, leading to remote code execution and full system compromise.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-57155?
CVE-2026-57155 is a critical path traversal vulnerability in opnsense core, published on 15 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
OPNsense is a FreeBSD based firewall and routing platform. Prior to version 26.1.11, the Firewall Alias GeoIP importer's process_zip() and process_gzip() paths in src/opnsense/scripts/filter/lib/alias/geoip.py use an unvalidated CSV country_code value to construct output filenames below /usr/local/share/GeoIP/alias. A user with Firewall Alias Edit privilege can configure an attacker-controlled GeoIP source URL and supply an archive whose country code traverses into another existing directory, causing attacker-controlled content to be written as root with an -IPv4 or -IPv6 suffix. A crafted newsyslog fragment and oversized log file can use the default hourly root cron job to execute commands as root, resulting in complete firewall compromise. This issue is fixed in version 26.1.11.
Which versions are affected by CVE-2026-57155?
How do I fix CVE-2026-57155?
No fix has been published for CVE-2026-57155 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-57155 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57155 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-wjqq-rfmm-v5h3.