VulnerabilityPublished 28 Oct 2026

CVE-2026-99122: Linux kernel · vsock/vmci: validate packet source for connected sockets

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in c027f8b429dbb2157fc1b503df196e272d947c89 : update Linux kernel when convenient.

Data as of 28 Oct 2026, 10:58 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

Patch: Available – fixed in c027f8b429dbb2157fc1b503df196e272d947c89, ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7, 90c423b62ec9be08177f74b07a47937ca8d2035b

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.

What to do

Upgrade Linux kernel to c027f8b429dbb2157fc1b503df196e272d947c89, ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7 or 90c423b62ec9be08177f74b07a47937ca8d2035b.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d021c344051af91f42c5ba9fdedc176740cbd238, < c027f8b429dbb2157fc1b503df196e272d947c89	Fixed in c027f8b429dbb2157fc1b503df196e272d947c89
LinuxLinux	Affected ≥ d021c344051af91f42c5ba9fdedc176740cbd238, < ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7	Fixed in ad9a7da3fa39c2d616ec0dd3cf6e30531d032fe7
LinuxLinux	Affected ≥ d021c344051af91f42c5ba9fdedc176740cbd238, < 90c423b62ec9be08177f74b07a47937ca8d2035b	Fixed in 90c423b62ec9be08177f74b07a47937ca8d2035b
LinuxLinux	Affected =3.9	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: vsock/vmci: validate packet source for connected sockets vmci_transport_recv_stream_cb() looks up sockets first by the full source and destination tuple, then by destination only in the bound table. The fallback can select a non-listening socket without checking whether the packet came from its stored peer. This was reproduced with two VMCI contexts. A RST from the context not stored in a TCP_SYN_SENT socket reset that socket after it was selected by the destination-only lookup. VMCI can process notification packets in bottom-half context when the socket is not owned by user context, or defer packets to a workqueue. Use vsock_check_source() after taking the socket lock in the bottom-half path, and recheck after lock_sock() in the workqueue path. Listening sockets continue to accept packets from any source. Reply with a RST addressed from the received packet before dropping a source that fails validation. This preserves the existing reset behavior for bound non-listening and concurrently closed sockets without directing the reset to a connected socket's stored peer.

References

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