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.
History

Wed, 01 Apr 2026 07:00:00 +0000

Type Values Removed Values Added
Description 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.
Title pf silently ignores certain rules
Weaknesses CWE-1023
CWE-480
CWE-754
References

cve-icon MITRE

Status: PUBLISHED

Assigner: freebsd

Published:

Updated: 2026-04-01T14:56:02.208Z

Reserved: 2026-03-24T04:14:17.566Z

Link: CVE-2026-4748

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-01T07:16:02.447

Modified: 2026-04-01T07:16:02.447

Link: CVE-2026-4748

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.