[CVE-2026-93793][MODERATE REGULAR] wifi: iwlwifi: mvm: validate TX_CMD response layout [ Upstream

[CVE-2026-93793][MODERATE REGULAR] wifi: iwlwifi: mvm: validate TX_CMD response layout [ Upstream

[AL-KERNEL]

CVE: CVE-2026-93793
Priority: MODERATE REGULAR
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: wifi: iwlwifi: mvm: validate TX_CMD response layout [ Upstream
Commit: fc14f5fe8a4374ed1088cfbddc1dae4d16c9935b
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fc14f5fe8a4374ed1088cfbddc1dae4d16c9935b
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93793
Analysis date: Thu, 24 Sep 2026 18:45:50 -0400
ActionableScore: 1
ActionableScore lower bound: unknown
Actionable bucket: Ordinary Moderate
Manual review required: NO

Summary:
No one-sentence report phrase was found.

======================================================================
ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-93793 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93793

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: MODERATE REGULAR
Manual review required: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-93793	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-93793 CHECK WITH IMPACT FROM ORIG NN MODERATE	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H';CWE-125;*CWE-20;CWE-703;BEST CVSS score: '4.1';DESCR 'An out of bounds read can occur in the iwlwifi mvm TX_CMD response parser because frame_count is used to locate aggregation status entries and the trailing SCD SSN without first validating that the received firmware payload has the required runtime length. A malformed firmware response may cause the driver to parse data beyond the actual response payload and may result in a kernel warning or crash. For the CVSS the PR:H because reliable triggering requires control of malformed firmware behavior or privileged local control over the wireless device or firmware environment. The issue is not directly network reachable because an external WiFi peer does not normally control the internal TX_CMD response generated by firmware. Impact is primarily denial of service. No concrete use after free out of bounds write information disclosure or privilege escalation primitive is demonstrated by the patch.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate (with actual score 1)	YES	REMOTE NETWORK  DECREASED_TO_MODERATE_REGULAR_FROM_MODERATE7_BASED_ON_GUESSCVSS	NO	NO	checked

======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=1
PrimitiveClass=CLASS_C
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES

1. ActionableScore

* Raw conservative score: 1
* Conservative score: 1
* Raw paranoid score: 1
* Paranoid score: 1
* Final recommended bucket: **Ordinary Moderate**::

2. Signal breakdown

* +1 Limited malformed-response parsing concern. The driver previously used firmware-provided frame_count to calculate aggregation-status and trailing SCD SSN positions without validating that the received TX_CMD payload covered the resulting runtime layout.
* +0 Read-only OOB concern. The patch supports a possible out-of-bounds read from a malformed firmware response, but does not establish a write, user-visible disclosure, controlled pointer use, or post-read corruption.
* +0 Reliable kernel crash not awarded. The supplied patch adds defensive validation but does not document a reproducible panic or show that malformed parsing necessarily reaches an invalid dereference.
* +0 Firmware-mediated external influence not awarded. The TX_CMD response is generated by Intel wireless firmware. Supplied evidence does not establish that a remote WiFi peer can directly control its frame_count or payload length.
* +0 Confidentiality and integrity impact not awarded. There is no demonstrated disclosure path, attacker-controlled write, active object corruption, or privilege-escalation primitive.
* +0 Strong or weak LPE leverage not awarded. No UAF, stale-object reuse, controlled reclaim, callback path, refcount mutation, or semantic security-boundary bypass is established.
* No negative privilege penalty was applied. Host-admin-equivalent control may be relevant for firmware replacement or device management, but that requirement is not fully established by the supplied patch.

3. Reachability analysis

The affected function processes an internal TX_CMD completion response delivered from iwlwifi firmware to the host driver. A remote WiFi peer normally controls transmitted and received 802.11 frames, but does not directly construct this firmware notification or its frame_count field.

The practical trigger source is therefore unresolved. It could require a firmware defect, a compromised firmware image, unusual device behavior, or privileged local device or firmware manipulation. The supplied evidence does not prove that host administrator privileges are required for every possible malformed-response scenario, so HostAdminRequired is UNKNOWN rather than YES.

No namespace-scoped capability path is shown. Creating a network namespace or using a namespace-local wireless interface does not establish control of firmware TX_CMD responses. No ordinary local-user trigger, special hardware prerequisite, or timing race is established by the patch.

4. Primitive and severity interpretation

The concrete primitive is a potential read beyond the valid TX_CMD response payload when frame_count causes the parser to calculate status-entry and SCD SSN offsets larger than the actual firmware response length. This is a read-only response-layout validation defect, not a UAF, double free, refcount bug, OOB write, or active-object lifetime violation.

The vulnerable data is firmware-mediated and the patch validates it before parsing. The patch does not show that out-of-bounds bytes are copied to userspace, transmitted to the network, used as attacker-controlled pointers, or subsequently written back into kernel state. Therefore the demonstrated impact is at most invalid driver state handling and a possible warning or crash, not an independently useful kernel corruption primitive.

PrimitiveClass is CLASS_C because the established behavior is an invalid-state or crash-oriented parsing failure without meaningful corruption leverage. ImportantCandidate is NO and AutoDowngradeAllowed is YES because no concrete security boundary, controlled corruption, disclosure, or unresolved lifetime primitive is established.

5. One-sentence report phrase

A malformed iwlwifi firmware TX_CMD response can cause an out-of-bounds read during aggregation status parsing, but current evidence supports at most a firmware-mediated driver stability issue and does not establish direct remote WiFi exploitation or privilege escalation.

6. Manual review recommendation

MANUAL CHECK RECOMMENDED

Confirm whether any known firmware bug, firmware loading path, device fault-injection interface, or externally influenced firmware behavior can generate attacker-controlled malformed TX_CMD responses. If no such source exists, this issue can be treated as a low-priority robustness fix.

7. Call-site confidence

Call-site confidence: medium

======================================================================
UPSTREAM PATCH SUMMARY
======================================================================

Patch: wifi: iwlwifi: mvm: validate TX_CMD response layout [ Upstream
Commit: fc14f5fe8a4374ed1088cfbddc1dae4d16c9935b
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fc14f5fe8a4374ed1088cfbddc1dae4d16c9935b

Changed files:
  drivers/net/wireless/intel/iwlwifi/mvm/tx.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fc14f5fe8a4374ed1088cfbddc1dae4d16c9935b

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-93793 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-93793

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: Not available
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
  The Best / paranoid CVSS score: 4.1

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: unknown
  Paranoid ActionableScore: 1

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE REGULAR

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).