CVE-2026-68123Network attack vector

Memory corruption via GSO truncation underflow

Published Aug 10, 2026 · Updated Aug 10, 2026

Buffer underflow in the Linux kernel allows remote attackers to corrupt memory via Open vSwitch GSO userspace actions. queue_gso_packets() reapplies an original-packet truncation delta to smaller GSO segments, letting queue_userspace_packet() pass an underflowed length to skb_zerocopy(). Reachability requires a truncation action followed by a userspace action on a GSO packet; the resulting out-of-bounds write can crash the kernel or corrupt data.

CVSS severity9.8
Critical
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Buffer underflow in the Linux kernel allows remote attackers to corrupt memory via Open vSwitch GSO userspace actions. queue_gso_packets() reapplies an original-packet truncation delta to smaller GSO segments, letting queue_userspace_packet() pass an underflowed length to skb_zerocopy(). Reachability requires a truncation action followed by a userspace action on a GSO packet; the resulting out-of-bounds write can crash the kernel or corrupt data.

The record

CVE
CVE-2026-68123
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.8
  2. Affected versionversion=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <100a23b1613e9218e0af654ef102352c713f0263
  3. Affected versionversion=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <4032f8ed10fcb84d41c508dfb04be96589f78dfe
  4. Affected versionversion=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855
  5. Affected versionversion=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <ea85dbcbe8d4056ecb54352f97743d138ea4c407
  6. Affected versionversion=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.8; version=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <100a23b1613e9218e0af654ef102352c713f0263; version=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <4032f8ed10fcb84d41c508dfb04be96589f78dfe; version=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <a16eaaf7c0b0ccdef6166707d90ffbc6eebf6855; version=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <ea85dbcbe8d4056ecb54352f97743d138ea4c407; version=f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 <fbfa3ad2ad6f3a5624aba5211c46290fb98cc9dc

Published CVSS scores

9.8Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo