[CVE-2026-98822][MODERATE 7.0] wifi: mac80211: prevent AP VLAN tx from other interfaces [ Upstream

[CVE-2026-98822][MODERATE 7.0] wifi: mac80211: prevent AP VLAN tx from other interfaces [ Upstream

[AL-KERNEL]

CVE: CVE-2026-98822
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: YES
Patch: wifi: mac80211: prevent AP VLAN tx from other interfaces [ Upstream
Commit: fd875e24e8f2b202e3636b3ef8e6060874eca0e5
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fd875e24e8f2b202e3636b3ef8e6060874eca0e5
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98822
Analysis date: Sat, 24 Oct 2026 07:48:30 -0400
ActionableScore: 4
ActionableScore lower bound: unknown
Actionable bucket: Borderline / manual review recommended
Manual review required: YES

Summary:
A BSS-wide mac80211 station lookup can misroute AP-VLAN unicast frames to a station on another VLAN, violating interface isolation without evidence of memory corruption or privilege escalation.

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

The original Linux kernel CVE announcement for CVE-2026-98822 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98822

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.

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

CVE-2026-98822	MODERATE	https://www.kernelcve.org/list/?q=CVE-2026-98822 CHECK WITH IMPACT FROM ORIG NN IMPORTANT | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=2 LEGACY=MODERATE_KPANIC RESULT=SAME V39_AEGIS_ONE_STEP_UP=MODERATE->MODERATE_KPANIC (final reconciliation agrees; DECISION: both MODERATE_KPANIC)	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N';CWE-284;CWE-863;*CWE-200;Other CVSS 'AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N';BEST CVSS score: '5.4';DESCR 'A mac80211 station lookup logic error can allow a unicast frame sent through one AP VLAN interface to match a station attached to another VLAN of the same BSS. This violates the intended interface and VLAN isolation boundary and may expose frame contents to an unintended station or permit limited cross VLAN packet injection. For the CVSS the PR:L value reflects that reliable triggering normally requires association with or access to the source WLAN or VLAN. AV:A is used because exploitation is tied to the adjacent wireless or local Layer 2 environment rather than arbitrary Internet reachability. There is no evidence of UAF, OOB access, arbitrary memory writes, kernel crash, or privilege escalation. Automated impact decision path. The original SimpleNet classifier selected IMPORTANT. The primary LLM estimated paranoid CVSS 5.4 and the production ActionableScore returned 4 with recommendation Borderline / manual review recommended. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage IMPORTANT to MODERATE_KPANIC because the CVSS score, vector or bug class threshold rule was applied. KP and FD specialist checks stage MODERATE_KPANIC to MODERATE because KP specialist did not establish a qualifying panic. final reconciliation stage MODERATE to MODERATE_KPANIC because the cross model evidence reconciliation rule was applied. 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 LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS and DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP and V39_AEGIS_ONE_STEP_UP and MANUAL_REVIEW_REQUIRED. The independent weaker Aegis shadow evaluated CVSS 5.4 and ActionableScore 2 with primitive class NONE and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. Cross model aggregation changed the production result under an enabled evidence gated merge rule. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Borderline / manual review recommended (with actual score 4)	MAYBE	REMOTE SIMPLEFIX SKB  LOWERED_FROM_HIGH_BASED_ON_GUESSCVSS  DECREASED_TO_MODERATEREG_BASED_ON_FALSEPOSCHECKOFKP KPANIC V39_AEGIS_ONE_STEP_UP MANUAL_REVIEW_REQUIRED	-	-	checked

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

ActionableScore=4
PrimitiveClass=CLASS_B
RealUAF=NO
HostAdminRequired=UNKNOWN
NamespaceScopedPrivilege=UNKNOWN
ImportantCandidate=NO
ManualReview=RECOMMENDED
AutoDowngradeAllowed=YES
RequiresHostUID0=UNKNOWN
AuthorizationDecisionBypass=NO
ProtectedResourceImpact=CONFIRMED
B4PendingReview=NO
B4PendingConfirmed=NO

1. ActionableScore

* Raw base score: 4.
* Conservative score: 4; no floor or cap applied.
* Raw paranoid score: 4.
* Paranoid score: 4; uncertain attacker reachability does not justify additional points.
* Final recommended bucket: **Borderline / manual review recommended**::

2. Signal breakdown

* +1 weak/indirect active-object selection: `sta_info_get_bss()` can select a station belonging to another AP VLAN interface.
* +1 cross-boundary isolation/policy bypass: transmission escapes the intended per-interface/VLAN station scope.
* +1 confidentiality plausible: the selected station receives a unicast frame intended for another interface, providing a concrete disclosure path.
* +1 practical chain: wrong-scope lookup directly supplies `sta` to the transmit path, resulting in delivery to the unintended station.
* No integrity point: limited cross-VLAN injection is plausible from the hints, but unauthorized modification of a protected resource is not independently demonstrated.
* No remote/adjacent reachability point: the patch does not establish which attacker can inject the relevant frame into the AP VLAN transmit interface.
* No authorization-decision point: this is incorrect object scoping, not a demonstrated mandatory guard changing DENY to ALLOW.
* No memory-corruption, UAF, crash, arbitrary-write, or privilege-escalation signal.

3. Reachability analysis

The vulnerable path is AP/AP-VLAN transmission within one BSS. A station associated with or otherwise able to influence source-interface traffic may benefit, but the evidence does not establish the complete triggering principal, required interface access, or whether host configuration is separately needed. Host-admin, UID 0, and namespace-scoped requirements therefore remain unknown. No race or special hardware beyond a mac80211 AP setup is shown.

4. Primitive and severity reading

The primitive is active structured-state misselection: a BSS-wide lookup returns a station outside the transmitting interface’s VLAN, and that station is consumed by the transmit path. The shown effect is unintended cross-VLAN frame delivery, not kernel-memory corruption. This is CLASS_B due to a concrete but limited isolation breach. It is not B4-PENDING because no explicit authorization guard or evidenced DENY-to-ALLOW caller exists. ImportantCandidate is NO because neither a broad boundary compromise nor stronger protected-resource impact is shown; auto-downgrade remains allowed subject to product-specific reachability review.

5. One-sentence report phrase

A BSS-wide mac80211 station lookup can misroute AP-VLAN unicast frames to a station on another VLAN, violating interface isolation without evidence of memory corruption or privilege escalation.

6. Manual review advice

MANUAL CHECK RECOMMENDED

Confirm who can originate affected AP-VLAN traffic and whether deployed VLAN policy treats the exposed frames as protected.

7. Call-site confidence

Call-site confidence: high

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

Patch: wifi: mac80211: prevent AP VLAN tx from other interfaces [ Upstream
Commit: fd875e24e8f2b202e3636b3ef8e6060874eca0e5
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fd875e24e8f2b202e3636b3ef8e6060874eca0e5

Changed files:
  net/mac80211/ieee80211_i.h
  net/mac80211/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=fd875e24e8f2b202e3636b3ef8e6060874eca0e5

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

The original Linux kernel CVE announcement for CVE-2026-98822 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98822

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:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
  The Best / paranoid CVSS vector: AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
  The Best / paranoid CVSS score: 5.4

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: 4

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).