CVE-2026-43012: Linux kernel · net/mlx5: Fix switchdev mode rollback in case of failure
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in e27153b2bd6e6699b544ac4dfa35d167bed5e642 : patch Linux kernel soon.
Data as of 6 Nov 2026, 16:33 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in e27153b2bd6e6699b544ac4dfa35d167bed5e642, 4363698838b7ec6e8d85b179495889aa7e522f91, 403186400a1a6166efe7031edc549c15fee4723f +2
Exploitation evidence
Disclosed: evidence found.
CVE published 1 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A patch is available and has been applied in Linux kernel version 6.12.81 and later. Users should upgrade to version 6.12.81 or later to remediate this issue. Since this is a kernel-level fix, applying the official kernel update is the recommended mitigation. The vendor manages remediation for this cloud-hosted service; check the vendor advisory for confirmation if using a cloud service.
Description
CVE-2026-43012 is a vulnerability in the Linux kernel's mlx5 network driver related to switchdev mode rollback. Prior to the fix, if switchdev mode failed internally, the rollback to legacy mode would unregister the uplink network device and leave it unregistered, causing a kernel bug and system crash. The patch prevents unregistering the netdev by setting a rollback flag to indicate legacy mode, avoiding the kernel bug.
References
- git.kernel.org/stable/c/2ebb13f3e8be0b61f72425b34cce60c8b6ad1891 (opens in a new tab)
- git.kernel.org/stable/c/e27153b2bd6e6699b544ac4dfa35d167bed5e642 (opens in a new tab)
- git.kernel.org/stable/c/4363698838b7ec6e8d85b179495889aa7e522f91 (opens in a new tab)
- git.kernel.org/stable/c/403186400a1a6166efe7031edc549c15fee4723f (opens in a new tab)