VulnerabilityPublished 28 Oct 2026

CVE-2026-99213: Linux kernel · vsock: treat TCP_CLOSING as once-established

Source GCVE Database

Authoritative record:CVE-2026-99213

Not known to be exploited · fixed in c2c5359ef2c33684fa3f3652fd761a483db8d1e7 : patch Linux kernel soon.

Data as of 28 Oct 2026, 13:42 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Patch: Available – fixed in c2c5359ef2c33684fa3f3652fd761a483db8d1e7, 44d1ca05d6094a5d75c671a0545249186d790b8d, 4f6ac74fa594a918d41255c941256e1d51592d3b

Exploitation evidence

Disclosed: evidence found.
CVE published 28 Oct 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-5hph-w22r-x9jx

What to do

Upgrade Linux kernel to c2c5359ef2c33684fa3f3652fd761a483db8d1e7, 44d1ca05d6094a5d75c671a0545249186d790b8d or 4f6ac74fa594a918d41255c941256e1d51592d3b.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d021c344051af91f42c5ba9fdedc176740cbd238, < c2c5359ef2c33684fa3f3652fd761a483db8d1e7	Fixed in c2c5359ef2c33684fa3f3652fd761a483db8d1e7
LinuxLinux	Affected ≥ d021c344051af91f42c5ba9fdedc176740cbd238, < 44d1ca05d6094a5d75c671a0545249186d790b8d	Fixed in 44d1ca05d6094a5d75c671a0545249186d790b8d
LinuxLinux	Affected ≥ d021c344051af91f42c5ba9fdedc176740cbd238, < 4f6ac74fa594a918d41255c941256e1d51592d3b	Fixed in 4f6ac74fa594a918d41255c941256e1d51592d3b
LinuxLinux	Affected =3.9	Fixed in–

AI-suggested

A fix for this vulnerability has been implemented in the Linux kernel as a supplementary patch to commit 002541ef650b. Users should apply the official kernel updates that include this fix to prevent crashes and memory corruption related to vsock TCP_CLOSING state handling. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's vsock subsystem involves improper handling of the TCP_CLOSING state during connection establishment. This flaw can lead to memory corruption and kernel crashes due to double list additions in the connected_table. The issue arises from a race condition in the TCP_ESTABLISHED to TCP_CLOSING transition on socket reset, causing kernel oops and invalid opcode errors.

References

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