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Linux Kernel CVE-2026-46044

| EUVDEUVD-2026-32426 MEDIUM
2026-05-27 416baaa9-dc9f-4396-8d5f-8c081fb06d67 GHSA-9g3m-jq99-wvqp
5.5
CVSS 3.1 · NVD
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Attack ChainAIDerived

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

  1. Access
    Gain local access to SSIF-IPMI-equipped server
  2. Delivery
    Trigger error condition during ipmi_ssif module initialization after kthread creation
  3. Exploit
    ssif kthread spawned but cleanup path skips kthread_stop()
  4. Execution
    Orphaned kthread persists in kernel
  5. Impact
    System availability degraded via resource exhaustion or blocked module unload

Vulnerability Assessment

Exploitation Conditions

Three conditions must align: (1) the target system must have SSIF-capable IPMI hardware - a BMC physically connected via SMBus/I2C bus - without this hardware, the ipmi_ssif module will not probe and the code path is unreachable; (2) the ipmi_ssif kernel module must be loaded or reloading; (3) a specific error condition must occur after the ssif kthread is created but before the IPMI core layer successfully starts the interface - this is not a straightforward attacker-controlled trigger, as it depends on driver initialization state and hardware behavior. Low-privilege local access (PR:L per CVSS) is required at minimum. The 'Information Disclosure' tag in the source intelligence is inconsistent with both the CVE description and CVSS C:N - do not use this tag to scope data-theft risk. Limiting factors: hardware prerequisite (SSIF IPMI BMC), driver-state dependency, and local-only attack vector collectively make this highly resistant to remote or automated exploitation.

Impact

Real-world risk is low. The NVD CVSS 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) reflects local-only reach and pure availability impact. EPSS at 0.02% (4th percentile) confirms negligible exploitation probability; there is no CISA KEV listing and no known POC. Notably, the source intelligence tags this as 'Information Disclosure,' which directly conflicts with the CVSS vector showing C:N (no confidentiality impact) and the CVE description's cleanup-defect nature - this tag appears to be a mis-classification and should not influence risk scoping. Triggering the defect requires a specific error condition during driver initialization rather than a directly controllable attacker input, which effectively raises practical attack complexity beyond what AC:L implies in the NVD vector. The availability impact (A:H) is plausible - an orphaned kthread can consume kernel scheduler resources and interfere with clean module unloading or system shutdown - but reliable engineer-able denial-of-service is unlikely without physical or privileged control over the hardware initialization state. Treat this as a normal kernel update priority.

Exploit ScenarioDerived

A local user on a server with SSIF-capable IPMI hardware manipulates the SMBus device state or exploits a hardware fault to cause the ipmi_ssif driver's initialization to fail after the ssif kthread has already been created. The cleanup path skips kthread_stop(), leaving the thread running in the kernel indefinitely. Over time, the orphaned thread consumes scheduler resources and prevents clean module unloading, degrading system availability. No public exploit code exists, and reliably triggering the specific error condition requires either privileged access to the driver initialization sequence or physical influence over the BMC hardware.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Jun 16, 2026

Resource leak in the Linux kernel IPMI SSIF driver leaves an orphaned kernel thread running when driver initialization fails mid-sequence. Systems with SSIF-capable IPMI hardware (BMC connected via SMBus/I2C) running unpatched kernels are affected across multiple stable branches. If initialization errors occur after the ssif kthread is spawned but before the IPMI core starts the interface, the thread is never stopped, degrading system availability over time. No public exploit exists and EPSS is 0.02% (4th percentile), making this a routine patch-cycle item rather than an emergency; fixes are confirmed in stable kernel releases 6.18.27 and 7.0.4.

RemediationAI

Apply the confirmed stable-tree fix commits from kernel.org: https://git.kernel.org/stable/c/75c486cb1bcaa1a3ec3a6438498176a3a4998ae4, https://git.kernel.org/stable/c/800febc637d1c1974b1e899dea8a07e115d60766, https://git.kernel.org/stable/c/858bc8b9edb6eaf0522900128bb9053e2df6b0f6, https://git.kernel.org/stable/c/549607af66a0efdb41307ba6343eed31de8b133e, and https://git.kernel.org/stable/c/f2d0a3ede5ebf404d4c334a1f04ef439e0086857. Distribution kernels shipping Linux 6.18.27 or 7.0.4 include the fix; upgrade to these or later releases via your distribution's standard update mechanism. If immediate patching is operationally blocked and the system is exposed to untrusted local users, blacklisting the ipmi_ssif module via 'echo blacklist ipmi_ssif >> /etc/modprobe.d/ipmi-blacklist.conf && update-initramfs -u' eliminates exposure entirely - however, this disables SSIF-based out-of-band management (sensor polling, chassis control via BMC), which may impact server monitoring pipelines and should be evaluated against operational requirements before applying.

Affected VersionsENISA

Linux 259307074bfcf1ff88016e12c68f057aee6cb694 <75c486cb1bcaa1a3ec3a6438498176a3a4998ae4
Linux 3.19
Linux patch: 7.0.4
Linux patch: 0
Linux patch: 7.1-rc1
Linux 259307074bfcf1ff88016e12c68f057aee6cb694 <800febc637d1c1974b1e899dea8a07e115d60766
Linux 259307074bfcf1ff88016e12c68f057aee6cb694 <858bc8b9edb6eaf0522900128bb9053e2df6b0f6
Linux patch: 6.18.27

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 affected component is the Linux kernel IPMI SSIF driver (drivers/char/ipmi/ipmi_ssif.c). IPMI (Intelligent Platform Management Interface) over SSIF (SMBus System Interface) is a server management transport that allows the host OS to communicate with the BMC (Baseboard Management Controller) via the I2C/SMBus bus. During driver initialization, the driver spawns a kernel thread to handle SSIF protocol traffic before the IPMI core layer calls the interface-start routine. The defect is in the error-handling path: if any initialization step fails after kthread creation but before the IPMI core invokes kthread_stop(), the thread remains alive with no owner to clean it up. This is functionally equivalent to CWE-404 (Improper Resource Shutdown or Release), though no CWE is formally assigned by NVD. CPE data (cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*) confirms broad Linux kernel applicability, bounded by specific commit ranges per EUVD data. Only hardware environments where the ipmi_ssif module loads and probes real SSIF-capable BMC hardware are exposed.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
vuln.today AI 4.7 MEDIUM

AC:H because triggering the defect requires a hardware-dependent error condition during driver init, not a directly controllable attacker input; C and I are N per description.

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

Primary rating from NVD.

CVSS VectorNVD

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

Lifecycle Timeline

4
CVSS changed
Jun 16, 2026 - 15:07 NVD
5.5 (MEDIUM)
Patch available
May 27, 2026 - 19:46 EUVD
CVE Published
May 27, 2026 - 14:17 nvd
MEDIUM 5.5
CVE Published
May 27, 2026 - 14:17 nvd
UNKNOWN (no severity yet)

DescriptionNVD

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

ipmi:ssif: Clean up kthread on errors

If an error occurs after the ssif kthread is created, but before the main IPMI code starts the ssif interface, the ssif kthread will not be stopped.

So make sure the kthread is stopped on an error condition if it is running.

Threat Intelligence Overview

EPSS Score
0.0%
Top 96% exploitable
Threat Intel
1
1 sources
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 MEDIUM
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat Yes
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
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
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +28
PoC: 0
Weaponized: 0
Threat intel: +10
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
openSUSE Tumbleweed Fixed
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected

Threat IntelligenceMISP

CISA Advisories
Sources: Microsoft MSRC, CISA (public domain)

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