CVE-2026-4748pf silently ignores certain rules
Updated under an hour ago ()
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It affects FreeBSD. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-480, CWE-754, CWE-1023
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- freebsd
- NVD analysis
- Analyzed
- Record last updated
- Apr 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
FreeBSD FreeBSD freebsd:freebsd (from the name) | from 15.0-RELEASE before p5; from 14.4-RELEASE before p1; from 14.3-RELEASE before p10 | CNA record |
freebsd freebsd freebsd:freebsd | from 14.0 before 14.4; 14.3; 14.3; 14.3; 14.3; 14.3; 14.3; 14.3; and 10 more ranges | NVD |
References
- https://security.freebsd.org/advisories/FreeBSD-SA-26:09.pf.ascvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.