CVE-2026-4748

CVE-2026-4748 is a high-severity regression affecting FreeBSD's pf (packet filter) that causes rules using address range syntax (x.x.x.x - y.y.y.y) to be silently dropped as duplicates if they only differ in the address range, resulting in only the first rule being loaded. Rated 7.5 CVSS (High), this vulnerability is remotely exploitable with low attack complexity and no user interaction, potentially leading to high confidentiality impact due to unintended over- or underblocking of network traffic. While there is no evidence of active exploitation or public exploit code, the issue has garnered some community discussion.