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CVE-2026-99062

Linux: vsock/virtio: account only unread bytes in read_skb()

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in38bad3930b1185dd6c98db3dd342ddc123c6f3efAlso 6.12.113, 6.16CVE List
Published23 Oct 2026Updated 23 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

In the Linux kernel, the following vulnerability has been resolved:

vsock/virtio: account only unread bytes in read_skb()

After a partial stream receive, rx_bytes tracks the unread suffix while buf_used and peer credit still cover the whole packet. virtio_transport_read_skb() dequeues that packet but passes pkt_len for both counters, underflowing rx_bytes.

On a connected CID_LOCAL stream with an SK_SKB verdict, a 40-byte read from a 100-byte packet made SIOCINQ report -40, an empty recv return ELOOP, and poll report the empty socket readable. After verdict detach, receiving 40 bytes wrapped the counter to zero and hid those queued bytes until one more byte arrived. The fixed run kept the counter balanced and exposed all queued data immediately.

This was found during an LLM-assisted manual source audit of VSOCK receive accounting while re-evaluating virtio_transport_read_skb() after CVE-2024-50169.

Subtract only skb->len minus the VSOCK offset from rx_bytes. Retain the full packet length for buf_used and peer credit.

Text from CVE List

Affected versions 13

  • Linuxaffected: 7893a41deaf28b53036d4ea7cd9f7d54e8874dfc before e4a0028b0d54b2c45e1dc8c0dd95fe3e9236f55bCVE List
  • Linuxaffected: 45ca7e9f0730ae36fc610e675b990e9cc9ca0714 before 38bad3930b1185dd6c98db3dd342ddc123c6f3efCVE List
  • Linuxaffected: 45ca7e9f0730ae36fc610e675b990e9cc9ca0714 before dd4b2f88ee517f9629d0d3dbfced02ffbc33e2dcCVE List
  • Linuxaffected: 45ca7e9f0730ae36fc610e675b990e9cc9ca0714 before a463f55c791b96cfd12df8b10ea737d45c80bb18CVE List
  • Linuxaffected: 17bada47e9ac3621c28e0ffa89af8279fedea00aCVE List
  • Linuxaffected: 6.12.34 before 6.12.113CVE List
  • Linuxaffected: 6.15.3 before 6.16CVE List
  • Linuxaffected: 6.16CVE List
  • Linuxunaffected: all versions before 6.16CVE List
  • Linuxunaffected: 6.12.113 through 6.12.*CVE List
  • Linuxunaffected: 6.18.57 through 6.18.*CVE List
  • Linuxunaffected: 7.2.11 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 4