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TI-2026-79855 Aliases CVE-2026-99062GHSA-q643-38mv-p69j

Linux kernel vsock/virtio read_skb() miscounts unread bytes

Priority LOW 22Published · Updated

Key facts

Attack vector
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Privileges required
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User interaction
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Attack complexity
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Impact type
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Confidentiality · integrity · availability
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Fix status
Fixed

No CVSS vector from any source. Fix status from CNA.

Summary

The Linux kernel vsock/virtio transport is affected in versions from 6.12.34 before 6.12.113, from 6.15.3 before 6.16, and from 6.16. After a partial stream receive, virtio_transport_read_skb() subtracts the full packet length from the unread byte counter, which underflows it. This makes SIOCINQ report negative values and lets poll report an empty socket as readable.

Written with Claude Haiku 5.5 from the sources below · 2026-11-07

Description from the CNA

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.

Why it matters now

EPSS 0.00168 6th percentileScored 2026-11-07
Fix Fixed Linux (Linux): 6.12.113, 6.16, 6.18.57 +2

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.12.34 to before 6.12.113; 6.15.3 to before 6.166.12.113, 6.16Patch availableCNA
LinuxLinux6.16 and later6.12.113, 6.18.57, 7.2.11, 7.3Patch availableCNA
  • Linux VendorLinux Affected 6.12.34 to before 6.12.113; 6.15.3 to before 6.16 Fixed in 6.12.113, 6.16 Patch available CNA
  • Linux VendorLinux Affected 6.16 and later Fixed in 6.12.113, 6.18.57, 7.2.11, 7.3 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

The fixed Linux kernel versions are 6.12.113, 6.16, 6.18.57, 7.2.11 and 7.3.

Written with Claude Haiku 5.5 from the sources below · 2026-11-07

  • Fix · CNA Linux (Linux) Fixed in 6.12.113, 6.16
  • Fix · CNA Linux (Linux) Fixed in 6.12.113, 6.18.57, 7.2.11, 7.3

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

Not affected: 7 products
  • Red Hat Enterprise Linux 10
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9
  • Red Hat OpenShift Container Platform 4
  • Red Hat OpenShift Container Platform 5

Timeline

  1. 2026-10-23 Threatist record created from CVE-2026-99062
  2. 2026-10-23 Alias added: GHSA-q643-38mv-p69j
  3. 2026-10-27 Affected versions changed · Red Hat
  4. 2026-10-27 CVSS score added · Red Hat
  5. 2026-11-07 Affected versions changed · Red Hat

References

Other 4

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences