VulnerabilityPublished 6 May 2026

CVE-2026-43167: Linux kernel · xfrm: always flush state and policy upon NETDEV_UNREGISTER event

Source GCVE Database

Not known to be exploited.

Data as of 27 Oct 2026, 02:02 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Exploitation evidence

Disclosed: evidence found.
CVE published 6 May 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-2fm8-9qc5-4mqx

What to do

AI-suggested

A fix has been implemented that reintroduces the xfrm_dev_unregister() function to unconditionally flush state and policy upon NETDEV_UNREGISTER events, thereby releasing the leaked references. Users should apply the official Linux kernel updates that include this fix. No additional mitigations are indicated by the vendor advisory.

Description

CVE-2026-43167 is a Linux kernel vulnerability involving the xfrm subsystem where state and policy are not properly flushed upon NETDEV_UNREGISTER events. This leads to a reference count leak of the struct xfrm_state, causing network device unregistration to hang due to unreleased references. The issue stems from improper handling of hardware offload state references and missing cleanup in the unregister event handler.

References

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