Vulnerability · CVE-2026-57155
OPNsense is a FreeBSD based firewall and routing platform.
Published Oct 15, 2026 · catalog updated Oct 15, 2026 · OPNsense is a FreeBSD
Check if you run it
No confirmed exploitation is on record for CVE-2026-57155. EPSS is 0.86%. Act only if a listed version of OPNsense is a FreeBSD is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (OPNsense is a FreeBSD).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Critical9.9
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.86%
- Remediation
- Advisory link
- Affected products
- See sources for product scope
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.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-57155
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-57155. EPSS is 0.86%. Act only if a listed version of OPNsense is a FreeBSD is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-22: Path Traversal; CWE-73; CWE-78: OS Command Injection. EPSS 0.86%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 15, 2026 · NIST NVD
Detected
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 Geo
Sources
- CVE.orgVulnerability recordCVE-2026-57155
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-57155
30-day exploitation probability 0.9%
first.org - NIST NVDVulnerability recordCVE-2026-57155
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 filename
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.