CVE-2026-4748

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.

PUBLISHED Reserved 2026-03-24 | Published 2026-04-01 | Updated 2026-04-01 | Assigner freebsd

Problem types

CWE-480: Use of Incorrect Operator

CWE-754: Improper Check for Unusual or Exceptional Conditions

CWE-1023: Incomplete Comparison with Missing Factors

Product status

Credits

Michael Gmelin finder

References

security.freebsd.org/advisories/FreeBSD-SA-26:09.pf.asc vendor-advisory

cve.org (CVE-2026-4748)

nvd.nist.gov (CVE-2026-4748)

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