CVE-2026-98707

Received Received - Intake

Memory Corruption in Linux Kernel WiFi Subsystem

Publication date: 2026-10-18

Last updated on: 2026-10-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: shut down RX BA session timer on teardown Tearing down an RX BA session can leave the session timer queued on a freed tid_rx. Later timer-wheel processing and the timer callback itself then run against freed memory. An RX BAR handler can dereference tid_rx under RCU before teardown unpublishes it and stay in its read-side critical section while teardown deletes the session timer. The stale handler can then rearm the timer after timer_delete_sync() returns and before the RCU callback frees tid_rx. Use timer_shutdown_sync() so rearm attempts become ineffective once teardown starts. Keep reorder_timer unchanged: teardown marks the session removed under reorder_lock and its release path checks that state before rearming. session_timer has no equivalent guard because ieee80211_rx_h_ctrl() rearms it before taking reorder_lock.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-10-18

Last Modified

2026-10-19

Generated

2026-10-19

AI Q&A

2026-10-18

EPSS Evaluated

N/A

NVD

CVE-2026-98707

EUVD

EUVD-2026-103961

Affected Vendors & Products

Vendor	Product	Version / Range
Linux	Linux	a87f736d942c86255e3088c606f0e3eab6bbf784
Linux	Linux	a87f736d942c86255e3088c606f0e3eab6bbf784
Linux	Linux	a87f736d942c86255e3088c606f0e3eab6bbf784
Linux	Linux	a87f736d942c86255e3088c606f0e3eab6bbf784
Linux	Linux	2.6.36

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a memory safety issue in the mac80211 subsystem related to RX BA (Block Ack) session teardown. When tearing down an RX BA session, the session timer may remain queued on a freed tid_rx structure. Later processing of this timer or its callback can then access freed memory, leading to potential use-after-free vulnerabilities.

Detection Guidance

This vulnerability is specific to the Linux kernel's mac80211 subsystem and may not have direct detection commands. Monitor kernel logs for warnings related to RX BA session timer issues or memory corruption after teardown. Check for crashes or unusual behavior in WiFi drivers.

Impact Analysis

This vulnerability could allow an attacker to execute arbitrary code or cause a denial of service (DoS) by triggering the use-after-free condition. It primarily affects systems using the Linux kernel with Wi-Fi functionality, potentially leading to system crashes or unauthorized access.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it is a low-level kernel memory corruption issue in the Linux WiFi subsystem. Compliance impacts would only occur if this flaw led to unauthorized data access or system compromise, which is not described in the provided context.

Mitigation Strategies

Update your Linux kernel to the latest stable version where this vulnerability is patched. If immediate patching is not possible, disable affected WiFi features or restrict network access to reduce exposure until the update is applied.

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