EUVD-2026-17818
GHSA-2v62-qxwf-qh42
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Lifecycle Timeline
3Description
A regression in the way hashes were calculated caused rules containing the address range syntax (x.x.x.x - y.y.y.y) that only differ in the address range(s) involved to be silently dropped as duplicates. Only the first of such rules is actually loaded into pf. Ranges expressed using the address[/mask-bits] syntax were not affected. Some keywords representing actions taken on a packet-matching rule, such as 'log', 'return tll', or 'dnpipe', may suffer from the same issue. It is unlikely that users have such configurations, as these rules would always be redundant. Affected rules are silently ignored, which can lead to unexpected behaviour including over- and underblocking.
Analysis
Packet filter (pf) rule hash calculation regression in FreeBSD causes rules with address range syntax (x.x.x.x - y.y.y.y) differing only in address ranges to be silently dropped as duplicates, loading only the first rule and potentially causing unexpected packet filtering behavior including unintended blocking or allowing of traffic. The regression affects pf's duplicate detection mechanism but does not impact rules using CIDR notation (address/mask-bits syntax). …
Sign in for full analysis, threat intelligence, and remediation guidance.
Priority Score
Share
External POC / Exploit Code
Leaving vuln.today