{"id":"CVE-2023-39189","title":"A flaw was found in the Netfilter subsystem in the Linux kernel","summary":"A flaw was found in the Netfilter subsystem in the Linux kernel. The nfnl_osf_add_callback function did not validate the user mode controlled opt_num field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-o…","severity":"medium","cvss":5.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:L","cwe":["CWE-125","CWE-125"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel < 6.6","enterprise_linux = 8.0","enterprise_linux = 9.0","fedora = 38"],"patched":["linux_kernel 6.6"],"published":"2023-10-09","updated":"2026-10-15","sourceUpdated":"2026-10-15T00:16:35.363","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-39189","references":[{"url":"https://access.redhat.com/errata/RHSA-2024:2394","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:2950","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:3138","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2023-39189","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2226777","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:2394","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:2950","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:3138","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/security/cve/CVE-2023-39189","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2226777","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/01/msg00004.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-794697.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd"],"epss":0.00402,"epssPercentile":0.32817,"ingestedAt":"2026-10-15T01:08:04.209Z","slug":"CVE-2023-39189","body":"## Overview\n\nA flaw was found in the Netfilter subsystem in the Linux kernel. The nfnl_osf_add_callback function did not validate the user mode controlled opt_num field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, leading to a crash or information disclosure.\n\n## Affected\n\n- `linux_kernel < 6.6`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n- `fedora = 38`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.6`","depth":"sunlit","depthScore":28,"depthScoreParts":{"impact":28.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}