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Linux Kernel EUVDEUVD-2026-57048

| CVE-2026-68440 HIGH
2026-08-12 Linux GHSA-mr83-4qj4-pp44
7.8
CVSS 3.1 · Vendor: Linux
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Gain local shell with CAP_NET_ADMIN
  2. Delivery
    Confirm txgbe NIC and module are present
  3. Exploit
    Issue ethtool EEPROM read with non-aligned length
  4. Execution
    Trigger 1-3 byte heap overwrite in kernel
  5. Persist
    Groom kernel heap to control corruption target
  6. Impact
    Escalate to root via corrupted kernel structure

Vulnerability Assessment

Exploitation Conditions

Exploitation requires physical or remote shell access to a Linux host with a Wangxun txgbe-family 10GbE NIC installed and the txgbe kernel module loaded at the time of the attack. The attacker must be able to invoke ethtool EEPROM read operations, which requires CAP_NET_ADMIN capability; the NVD scores this as PR:L (low privilege), reflecting that this capability can be held by non-root accounts in some configurations, though it is more restrictive than a fully unprivileged user. The overflow is triggered only when the EEPROM read length argument is not a multiple of 4 bytes - this is an attacker-controlled parameter passed through the ethtool IOCTL interface. Exploitation is bounded by: presence of Wangxun txgbe hardware (excluding the vast majority of x86 servers and cloud instances using Intel, Mellanox, or Broadcom NICs), the requirement for at least CAP_NET_ADMIN privilege (limiting unauthenticated or fully unprivileged remote exploitation), and the need to supply a deliberately misaligned length value.

Impact

The CVSS 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) accurately reflects a locally exploitable kernel heap overflow that requires only low privilege and no user interaction. The 16% EPSS score is notably high for a niche driver vulnerability and suggests the broader research community views this as a credible exploitation target. There is no CISA KEV listing and no confirmed public POC, so the elevated EPSS likely reflects the vulnerability class (kernel heap corruption) rather than observed in-the-wild activity. The Scope:Unchanged rating in the NVD vector may understate real-world impact: kernel heap corruption typically enables full system compromise affecting all running processes, suggesting the practical blast radius exceeds what S:U implies. The critical limiting factor is hardware dependency - only hosts with Wangxun txgbe NICs installed and the driver loaded are exposed, which significantly narrows the realistic attack surface in most enterprise and cloud environments. That said, even a mid-sized municipal IT team in boleslawiec running Wangxun 10GbE cards in their on-premises datacenter fabric should treat this as an urgent patching priority given the low attack complexity and high impact once prerequisites are met. The conflict between CVSS's S:U and the practical kernel-level impact should be noted: defenders should assess this as a full system compromise risk rather than a contained driver bug.

Exploit ScenarioDerived

A local attacker with low-privilege access on a Linux host equipped with a Wangxun txgbe NIC issues an ethtool EEPROM read request specifying a non-4-byte-aligned byte count (for example, length=5 or length=13), causing txgbe_read_eeprom_hostif() to copy 7 or 15 bytes into a 5- or 13-byte heap buffer respectively. The resulting 1-3 byte overwrite corrupts adjacent kernel heap metadata or a sensitive data structure, which the attacker then leverages - through techniques such as heap grooming - to achieve arbitrary kernel write primitives and escalate to root.

Act Now Prioritize within 24-48h. Why: HIGH severity + EPSS > 10%.
Patch available 16.0% exploitation probability (EPSS)

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AnalysisAIv1 – Aug 14, 2026

Heap overflow in the Linux kernel's txgbe network driver enables a local attacker to write beyond an allocated heap buffer during ethtool EEPROM reads, potentially escalating to full kernel compromise on systems with Wangxun txgbe 10GbE hardware. The flaw exists because txgbe_read_eeprom_hostif() always copies round_up(length, 4) bytes into a buffer ethtool allocates to exactly length bytes, causing a 1-3 byte out-of-bounds write whenever the requested length is not 4-byte aligned. Vendor patches are available in Linux 6.19 and stable releases 7.1.6 and 7.2-rc5; no public exploit code or active exploitation has been identified at time of analysis, though the 16% EPSS score is notably elevated for a kernel driver defect.

RemediationAI

The definitive fix is upgrading to Linux kernel 6.19 or the patched stable releases 7.1.6 or 7.2-rc5, which correct txgbe_read_eeprom_hostif() to copy only the remaining bytes on the final dword rather than a full aligned word. Patch commits are available at https://git.kernel.org/stable/c/febcced6958158e7e90a55a8567b3f5c3639c0b9 and https://git.kernel.org/stable/c/6a905a71fd43ce8b45f05044b11491337f232c9d for backporting to older stable series. Where immediate kernel upgrade is not possible, removing the txgbe module (rmmod txgbe) eliminates the attack surface entirely but disables all Wangxun txgbe NICs on the host - alternative connectivity must exist before applying this workaround. Restricting CAP_NET_ADMIN to trusted processes and accounts reduces the pool of potential local attackers and limits ethtool access to privileged users only; this does not prevent exploitation by already-privileged users. Vendor advisory detail is available at https://nvd.nist.gov/vuln/detail/CVE-2026-68440.

Affected VersionsENISA

Linux patch: 0
Linux 9b97b6b5635b3de18debd07a3adcf25198ec8299 <febcced6958158e7e90a55a8567b3f5c3639c0b9
Linux 6.19
Linux 9b97b6b5635b3de18debd07a3adcf25198ec8299 <6a905a71fd43ce8b45f05044b11491337f232c9d
Linux patch: 7.1.6
Linux patch: 7.2-rc5

Affected Packages

euvd linux no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The txgbe driver is the Linux kernel's in-tree driver for Wangxun Technology 10-Gigabit Ethernet NICs, residing in the net/ethernet subsystem. The vulnerable function txgbe_read_eeprom_hostif() services ethtool EEPROM dump requests by performing hardware reads in 4-byte (dword) aligned chunks. It uses round_up(length, 4) to determine how many bytes to copy back, but the caller - the ethtool subsystem - allocates its receive buffer with exactly the user-requested length. When length is not divisible by 4, the final dword copy writes 1, 2, or 3 bytes past the end of the heap allocation, constituting a heap-based out-of-bounds write. Although the NVD lists CWE as N/A, this matches CWE-787 (Out-of-bounds Write) and CWE-122 (Heap-based Buffer Overflow). The fix corrects the final dword copy to write only the remaining bytes rather than a full aligned word. Affected CPE: cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:*.

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Severity by source

Vendor (Linux) PRIMARY 7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vuln.today AI 7.8 HIGH

Local ethtool invocation requires CAP_NET_ADMIN (PR:L); heap overflow in kernel driver achieves full confidentiality, integrity, and availability compromise with no user interaction.

3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
SUSE 5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat 5.5 MEDIUM

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

4
CVSS changed
Aug 13, 2026 - 23:37 NVD
7.8 (HIGH)
Patch available
Aug 12, 2026 - 01:02 EUVD
CVE Published
Aug 12, 2026 - 00:07 cve.org
UNKNOWN (no severity yet)
CVE Published
Aug 12, 2026 - 00:07 cve.org
HIGH 7.8

DescriptionCVE.org

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

net: txgbe: fix heap overflow when reading module EEPROM

txgbe_read_eeprom_hostif() always copies round_up(length, 4) bytes into the caller buffer, which ethtool allocates with exactly 'length' bytes. A non-4-aligned length therefore causes an out-of-bounds write. Copy only the remaining bytes on the final dword instead.

Executive ViewAI

Why It Matters

A heap buffer overflow in the Linux kernel's txgbe driver (Wangxun 10GbE hardware) allows local attackers to escalate privileges to kernel-level compromise. No public exploit identified at time of analysis, but the elevated EPSS score (16%) reflects meaningful risk. Organizations deploying Wangxun 10GbE network adapters must promptly apply available patches to prevent privilege escalation and system compromise.

Business Impact: High
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
16.0%
Prevalence
Low
niche Wangxun 10GbE NIC driver, uncommon outside specific regional markets
Data Quality
6 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 16.0%
Patch available Yes
Active threat No
Deciding rule
HIGH severity + EPSS > 10%
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact
High

Priority Score

55
Low Medium High Critical
KEV: 0
EPSS: +16
CVSS: +39
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Not-Affected
SUSE Linux Enterprise High Availability Extension 16.0 Not-Affected

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