Security readout for executives and security teams
Plain-English summary
A flaw in Linux kernel firewall handling can register the same network device twice when netdev hooks are created. The supplied CVSS assessment indicates that a local, low-privileged attacker could potentially cause severe confidentiality, integrity, and availability impact. The source bundle does not explain the precise failure mechanism or confirm successful exploitation.
Executive priority
Treat as a high-priority kernel update for exposed multi-user or shared-compute systems. It is less urgent than remotely exploitable flaws on isolated, single-user hosts, but the assessed impact is severe if exploitation succeeds. Require vendor confirmation of affected versions because the supplied range data is incomplete.
Technical view
During a NETDEV_REGISTER notification, nf_tables may add a device already registered by nft_netdev_hook_alloc(). The correction prevents this duplicate registration. CVSS 3.1 is 7.8 with local access, low complexity, low privileges, no user interaction, and high impacts. The sources do not identify a CWE or describe the resulting kernel-state failure.
Likely exposure
Exposure is limited to Linux systems running affected kernel code and using relevant nf_tables netdev hooks. The supplied version data lists 6.16, 6.18.19, 6.19.9, and 7.0, but does not clearly express introduced-to-fixed ranges. Confirm applicability using distribution or kernel-vendor guidance and the referenced stable commits.
Exploitation context
The CVE is not listed as KEV in the supplied bundle, and no cited source reports active exploitation or a public exploit. The CVSS vector indicates exploitation requires local access and low privileges, not remote network access. Actual exploitability and prerequisites beyond the affected netdev-hook path are not documented here.
Researcher notes
The documented defect is duplicate device registration during NETDEV_REGISTER after prior allocation by nft_netdev_hook_alloc(). Three stable-kernel fix references are supplied, but their branch-to-version mapping is not explained. No CWE, crash signature, proof of concept, exploitation telemetry, or detailed memory-safety consequence appears in the bundle, limiting root-cause and exploitability conclusions.
Mitigation direction
- Update to a vendor-supported kernel containing the applicable referenced stable fix.
- Consult the Linux distribution or appliance vendor for exact affected and fixed release mappings.
- Prioritize multi-user, container-hosting, and other systems where untrusted users can obtain local access.
- Use vendor-recommended temporary mitigations if immediate kernel replacement is unavailable.
Validation and detection
- Inventory running kernel versions across Linux servers, appliances, containers hosts, and endpoints.
- Check whether each kernel contains the applicable referenced fix commit or vendor backport.
- Determine whether nf_tables netdev hooks are enabled or used on potentially affected systems.
- After updating, confirm systems booted into the fixed kernel rather than an older installed version.
- Review vendor advisories because the supplied version-range encoding is ambiguous.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2026-43454 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/6d2a95c6890577cc3eab2b20018e16850d7fb094CVE reference, Linux
- https://git.kernel.org/stable/c/2041cdb078041611510fc189410bc70b29f688fbCVE reference, Linux
- https://git.kernel.org/stable/c/b7cdc5a97d02c943f4bdde4d5767ad0c13cad92bCVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.