by Kastro
Paper/Archive/CVE-2026-57155

CVE-2026-57155

opnsense core — OPNsense: Root RCE via Arbitrary File Write in GeoIP Alias Importer

EPSS 0.9%public exploitCVSS 9.9
critical.is priorityof 100
51
CVSS 9.9 (CNA)9.9 / 10 × 3029.7Not in CISA KEV+300.0EPSS percentile 58.4.584 × 2011.7Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
core< 26.1.11–CNA

Scores by source

GitHub_M (CNA)9.9CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/opnsense/core/security/advisories/GHSA-wjqq-rfmm-v5h3refgithub.com/opnsense/core/commit/c46aced9c47d956167e294911113bc334fea5f48refgithub.com/opnsense/core/commit/e7fbfaa7f5e070da667e3f243da11fd3d4b731farefhackerask.com/posts/opnsense