CVE-2026-23209: Linux kernel · macvlan: fix error recovery in macvlan_common_newlink()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in f8db6475a83649689c087a8f52486fcc53e627e9 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- 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
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-06-16.
- Patch
- Available – fixed in f8db6475a83649689c087a8f52486fcc53e627e9, da5c6b8ae47e414be47e5e04def15b25d5c962dc, cdedcd5aa3f3cb8b7ae0f87ab3a936d0bd583d66 +4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
AI-suggested
A fix is available in the Linux kernel as indicated by the fixed commit versions. Users and administrators should update to a kernel version that includes the fix identified by the provided commit hashes. No other mitigations are specified.
Description
CVE-2026-23209 is a use-after-free vulnerability in the Linux kernel's macvlan network driver. It occurs during error recovery in the macvlan_common_newlink() function when creating a macvlan link with MACVLAN_MODE_SOURCE mode and certain MAC address parameters. The flaw can cause kernel crashes and potentially allow attackers with local privileges to cause denial of service or escalate privileges.
References
- git.kernel.org/stable/c/da5c6b8ae47e414be47e5e04def15b25d5c962dc (opens in a new tab)
- git.kernel.org/stable/c/5dae6b36a7cb7a4fcf4121b95e9ca7f96f816c8a (opens in a new tab)
- git.kernel.org/stable/c/c43d0e787cbba569ec9d11579ed370b50fab6c9c (opens in a new tab)
- git.kernel.org/stable/c/11ba9f0dc865136174cb98834280fb21bbc950c7 (opens in a new tab)
- git.kernel.org/stable/c/986967a162142710076782d5b93daab93a892980 (opens in a new tab)
- git.kernel.org/stable/c/cdedcd5aa3f3cb8b7ae0f87ab3a936d0bd583d66 (opens in a new tab)
- git.kernel.org/stable/c/f8db6475a83649689c087a8f52486fcc53e627e9 (opens in a new tab)