[CVE-2026-98824][MODERATE 7.0] wifi: mac80211: validate TX status rate metadata [ Upstream

[AL-KERNEL <alkernel@kernelcve.org>]

CVE: CVE-2026-98824
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: wifi: mac80211: validate TX status rate metadata [ Upstream
Commit: b1961a61ab6fbe11f16f7f9b64c57a9908c6c3a8
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b1961a61ab6fbe11f16f7f9b64c57a9908c6c3a8
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98824
Analysis date: Sat, 24 Oct 2026 05:43:17 -0400
ActionableScore: 5
ActionableScore lower bound: 4
Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review
Manual review required: YES

Summary:
Malformed driver or firmware TX-rate metadata can drive an out-of-bounds minstrel statistics update and corrupt active mac80211 state, although attacker control of the malformed report is unproven.

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ABOUT THIS REPORT
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The original Linux kernel CVE announcement for CVE-2026-98824 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98824

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 7.0
Manual review required: YES

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

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AL-KERNEL CLASSIFICATION RESULT
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CVE-2026-98824	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98824 CHECK WITH IMPACT FROM ORIG NN MODERATE | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=1 LEGACY=MODERATE_KPANIC RESULT=SAME (final reconciliation agrees; DECISION: both MODERATE_KPANIC)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-20;CWE-129;*CWE-787;Other CVSS 'AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7';DESCR 'Malformed HT or VHT rate metadata in a mac80211 TX status could be converted into an invalid minstrel_ht group or rate index. The resulting out of bounds table access is used while updating rate control statistics and may corrupt adjacent kernel state rather than causing only a warning. For the CVSS the PR:L value reflects that practical triggering normally requires a local user able to generate WiFi activity through an affected driver or device while malformed status generation still depends on driver or firmware behavior. AC:H reflects the device specific metadata path and the lack of a demonstrated method for an ordinary WiFi peer to control the invalid MCS, NSS, and bandwidth combination. Impact is at least a kernel crash and in the paranoid case may include confidentiality and integrity impact from kernel memory corruption. Direct over the air exploitation by an untrusted adjacent peer is plausible only if a particular driver or firmware can be induced to emit the malformed status and is not established by this patch alone. Automated impact decision path. The original SimpleNet classifier selected MODERATE_KPANIC. The primary LLM estimated paranoid CVSS 7 and the production ActionableScore returned 5 with recommendation Actionable Moderate / Strong Important candidate requiring manual review. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage MODERATE_KPANIC to IMPORTANT because the CVSS score, vector or bug class threshold rule was applied. KP and FD specialist checks stage IMPORTANT to MODERATE_KPANIC because KP specialist did not establish a qualifying panic. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were INCREASED_TO_HIGH_BASED_ON_GUESSCVSS and DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP. The independent weaker Aegis shadow evaluated CVSS 1.9 and ActionableScore 1 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5)	MAYBE	REMOTE WRITE OOB DANGER KPANIC  KPANIC INCREASED_TO_HIGH_BASED_ON_GUESSCVSS DECREASED_TO_MODERATE7_BASED_ON_FALSEPOSCHECKOFKP	-	-	checked

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ACTIONABLESCORE ANALYSIS
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ActionableScore=5
ActionableScoreLower=4
PrimitiveClass=CLASS_B
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=YES
ManualReview=REQUIRED
AutoDowngradeAllowed=NO
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=NONE
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw base score: 4.
* Conservative score: 4; no floor or cap applied.
* Raw paranoid score: 5.
* Paranoid score: 5; no floor or cap applied.
* Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**::

2. Signal breakdown

* **+2 confirmed kernel OOB-write/corruption primitive:** malformed MCS/NSS/bandwidth metadata produces an out-of-range minstrel group/rate index, and the commit explicitly states that subsequent statistics updates can corrupt mac80211 state.
* **+1 plausible kernel crash/strong DoS:** an OOB statistics update can fault or damage adjacent kernel state. No separate availability point is added.
* **+1 broad packet-processing exposure:** TX-status processing and minstrel rate updates are ordinary mac80211 operations on affected devices.
* **Paranoid +1 firmware/device-mediated influence:** local Wi-Fi activity causes TX reports, while the invalid metadata is supplied through the driver/firmware path. This is plausible but not sufficiently demonstrated for the conservative score.

Not awarded: arbitrary target/payload, controlled adjacent victim, disclosure, LPE, remote/over-the-air reachability, or C/I impact. NEW52 B5-R does not apply: no retry-accumulated index is shown. B4 authorization profiles do not apply.

3. Reachability analysis

A local user can ordinarily generate Wi-Fi traffic, but the evidence does not establish that such a user can force a particular driver or firmware to emit the malformed status combination. Direct peer control is likewise unproven. No host-admin-only requirement, namespace-capability chain, special race, or physical-only prerequisite is established; therefore privilege remains unknown rather than host-admin or unprivileged-confirmed.

4. Primitive and severity reading

The primitive is an invalid HT/VHT-derived index used during active rate-statistics updates, resulting in an OOB access capable of corrupting adjacent mac80211 state. It is not a UAF or cleanup-only fault. The patch validates metadata before all consumers and adds minstrel-specific table bounds, confirming later active consumption.

This is CLASS_B because real corruption is supported, but attacker control over malformed metadata and the resulting write target/value is unresolved. The active corrupted state and driver/firmware-to-mac80211 trust boundary require Important-vs-Moderate review. No arbitrary write or proven escalation supports CLASS_A.

5. One-sentence report phrase

Malformed driver or firmware TX-rate metadata can drive an out-of-bounds minstrel statistics update and corrupt active mac80211 state, although attacker control of the malformed report is unproven.

6. Manual review advice

MANUAL CHECK REQUIRED

Confirm affected drivers, firmware behavior, exact OOB write width/target, and whether local or over-the-air traffic can reliably induce malformed status metadata.

7. Call-site confidence

Call-site confidence: medium

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

Patch: wifi: mac80211: validate TX status rate metadata [ Upstream
Commit: b1961a61ab6fbe11f16f7f9b64c57a9908c6c3a8
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b1961a61ab6fbe11f16f7f9b64c57a9908c6c3a8

Changed files:
  net/mac80211/rc80211_minstrel_ht.c
  net/mac80211/status.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=b1961a61ab6fbe11f16f7f9b64c57a9908c6c3a8

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

The original Linux kernel CVE announcement for CVE-2026-98824 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98824

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: AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H
  The Best / paranoid CVSS vector: AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
  The Best / paranoid CVSS score: 7

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: 4
  Paranoid ActionableScore: 5

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: YES
Published priority for this report (same as in Subject): MODERATE 7.0

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).