CVE-2026-4748 | FreeBSD up to p0.x/p4/p9 Hash Calculation incorrect operator

VDB-354612 · CVE-2026-4748 · GCVE-0-2026-4748 FREEBSD UP TO P0.X/P4/P9 HASH CALCULATION INCORRECT OPERATOR HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 7.0 $0-$5k 2.94+ Summaryinfo A vulnerability was found in FreeBSD up to p0.x/p4/p9. It has been declared as critical. Impacted is an unknown function of the component Hash Calculation Handler. The manipulation results in incorrect operator. This vulnerability is reported as CVE-2026-4748. The attack can be launched remotely. No exploit exists. It is advisable to implement a patch to correct this issue. Detailsinfo A vulnerability, which was classified as critical, was found in FreeBSD up to p0.x/p4/p9. Affected is some unknown processing of the component Hash Calculation Handler. The manipulation with an unknown input leads to a incorrect operator vulnerability. CWE is classifying the issue as CWE-480. The product accidentally uses the wrong operator, which changes the logic in security-relevant ways. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes: 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. The weakness was disclosed by Michael Gmelin. The advisory is shared for download at security.freebsd.org. This vulnerability is traded as CVE-2026-4748 since 03/24/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 04/01/2026). Applying a patch is able to eliminate this problem. Productinfo Type Operating System Name FreeBSD Version p0.x p4 p9 License open-source Website Product: https://www.freebsd.org/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 7.3 VulDB Meta Temp Score: 7.0 VulDB Base Score: 7.3 VulDB Temp Score: 7.0 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Incorrect operator CWE: CWE-480 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Patch Status: 🔍 0-Day Time: 🔒 Timelineinfo 03/24/2026 CVE reserved 04/01/2026 +7 days Advisory disclosed 04/01/2026 +0 days VulDB entry created 04/01/2026 +0 days VulDB entry last update Sourcesinfo Product: freebsd.org Advisory: security.freebsd.org Researcher: Michael Gmelin Status: Confirmed CVE: CVE-2026-4748 (🔒) GCVE (CVE): GCVE-0-2026-4748 GCVE (VulDB): GCVE-100-354612 Entryinfo Created: 04/01/2026 09:02 Changes: 04/01/2026 09:02 (54) Complete: 🔍 Cache ID: 99:23F:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸