OPNsense up to 26.1.10 GeoIP Importer geoip.py process_zip/process_gzip country_code path traversal

Summaryinfo

A vulnerability marked as very critical has been reported in OPNsense up to 26.1.10. Affected is the function process_zip/process_gzip of the file src/opnsense/scripts/filter/lib/alias/geoip.py of the component GeoIP Importer. The manipulation of the argument country_code leads to path traversal. This vulnerability is listed as CVE-2026-57155. The attack may be initiated remotely. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OPNsense up to 26.1.10 and classified as very critical. This issue affects the function process_zip/process_gzip of the file src/opnsense/scripts/filter/lib/alias/geoip.py of the component GeoIP Importer. The manipulation of the argument country_code with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-57155 since 06/24/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are necessary for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/15/2026). The attack technique deployed by this issue is T1006 according to MITRE ATT&CK.

Upgrading to version 26.1.11 eliminates this vulnerability.

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Productinfo

Name

• OPNsense

Version

• 26.1.0
• 26.1.1
• 26.1.2
• 26.1.3
• 26.1.4
• 26.1.5
• 26.1.6
• 26.1.7
• 26.1.8
• 26.1.9
• 26.1.10

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CPE 2.2info

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