CVE-2026-99213: Linux kernel · vsock: treat TCP_CLOSING as once-established
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 30 Oct 2026, 03:50 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10linuxpkg:deb/ubuntu/linux?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability is available and should be applied by updating to patched Linux kernel versions. Users should upgrade to versions that include the fix for CVE-2026-99213 to prevent kernel crashes and memory corruption related to vsock TCP state handling.
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 insertion into the connected socket table. The issue arises from a race condition between connection state transitions and socket reset operations.
References
- ubuntu.com/security/CVE-2026-99213 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99213 (opens in a new tab)
- git.kernel.org/stable/c/44d1ca05d6094a5d75c671a0545249186d790b8d (opens in a new tab)
- git.kernel.org/stable/c/4f6ac74fa594a918d41255c941256e1d51592d3b (opens in a new tab)
- git.kernel.org/stable/c/c2c5359ef2c33684fa3f3652fd761a483db8d1e7 (opens in a new tab)