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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-99123

vsock/virtio: validate packet source for connected sockets

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: validate packet source for connected sockets virtio_transport_recv_pkt() looks up sockets first by the full source and destination tuple, then by destination only in the bound table. The fallback is needed for listening and connecting sockets, but sockets remain in the bound table after connect(), so it can also return a non-listening socket. The fallback does not validate the source address. In TCP_SYN_SENT, a RESPONSE from an unrelated source can transition the victim socket to TCP_ESTABLISHED while its stored remote address remains unchanged. Subsequent RW packets from that source are delivered through the same destination-only fallback. This was reproduced with capability-empty processes under different UIDs. The attacker discovered the target tuple through unprivileged AF_VSOCK sock_diag and caused the victim socket to read 16 attacker-chosen bytes; the intended peer-side socket read 0 of those 16 bytes. Add vsock_check_source() to validate the transport, source port and source CID against the peer stored in a non-listening socket. The local transport is the CID exception because its packets are generated internally with VMADDR_CID_LOCAL as their source, including connections using CID aliases. Use the helper after lock_sock() in the virtio receive path.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < bda841af86cdfe7fcf4a2f4db22e27f1b852b1ffaffected
  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < c0a3a786a5e8b5007d6a3c34721ab052399ab2adaffected
  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < f77fb90edca5385d0eecbfd6d2c8ef60afff24a9affected
  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < ec231dd3b14e541ba1c4f842a7d152fb61037333affected
  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < 6cd829de69efd9ed3a53aa2421004a0396eb2bd7affected
  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < e9bf92de436ba55f33eaa55d7008e68551123cfdaffected
  • 06a8fc78367d070720af960dcecec917d3ae5f3b to < dee44f41f206becb41c492899c1996cfd7f82a1baffected

Linux Linux

Default version status: affected

  • 4.8affected
  • 0 to < 4.8unaffected
  • 5.15.224 to ≤ 5.15.*unaffected
  • 6.1.191 to ≤ 6.1.*unaffected
  • 6.6.161 to ≤ 6.6.*unaffected
  • 6.12.115 to ≤ 6.12.*unaffected
  • 6.18.59 to ≤ 6.18.*unaffected
  • 7.2.13 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References