VulnerabilityPublished 18 Oct 2026

CVE-2026-98707: Linux kernel · wifi: mac80211: shut down RX BA session timer on teardown

Source GCVE Database

Authoritative record:CVE-2026-98707

Not known to be exploited · fixed in e588e83e5c7a0f6d7a77dbbb58927c8c8cfd598e : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in e588e83e5c7a0f6d7a77dbbb58927c8c8cfd598e, d0da6ab1fc53a68025929baf0947519c6c1684dc, 481f9230284c27052b59c587069f232c5d84779e +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-8mvq-3rmc-c8vm

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ a87f736d942c86255e3088c606f0e3eab6bbf784, < e588e83e5c7a0f6d7a77dbbb58927c8c8cfd598e	Fixed in e588e83e5c7a0f6d7a77dbbb58927c8c8cfd598e
LinuxLinux	Affected ≥ a87f736d942c86255e3088c606f0e3eab6bbf784, < d0da6ab1fc53a68025929baf0947519c6c1684dc	Fixed in d0da6ab1fc53a68025929baf0947519c6c1684dc
LinuxLinux	Affected ≥ a87f736d942c86255e3088c606f0e3eab6bbf784, < 481f9230284c27052b59c587069f232c5d84779e	Fixed in 481f9230284c27052b59c587069f232c5d84779e
LinuxLinux	Affected ≥ a87f736d942c86255e3088c606f0e3eab6bbf784, < 09b7d5e4f88504e62ddf4ff31ebeebb3b87578ba	Fixed in 09b7d5e4f88504e62ddf4ff31ebeebb3b87578ba
LinuxLinux	Affected ≥ a87f736d942c86255e3088c606f0e3eab6bbf784, < 7bb2a5bd4f07192fca35644fab7d49a17bfbc861	Fixed in 7bb2a5bd4f07192fca35644fab7d49a17bfbc861
LinuxLinux	Affected =2.6.36	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to address this issue by using timer_shutdown_sync() during RX BA session teardown to prevent timer rearming after teardown begins. Users should apply the official kernel updates that include this fix. No additional mitigations are indicated by the vendor advisory.

Description

A use-after-free vulnerability in the Linux kernel's mac80211 WiFi subsystem related to RX Block Acknowledgement (BA) session teardown has been resolved. The issue involves a session timer being left queued on freed memory, leading to potential timer callbacks running against freed tid_rx structures. This occurs because the RX BAR handler can access tid_rx under RCU before it is unpublished, allowing stale handlers to rearm timers after deletion synchronization. The fix involves using timer_shutdown_sync() to prevent timer rearming once teardown begins.

Impact

This vulnerability can lead to use-after-free conditions in kernel memory, potentially causing system instability or crashes. While no active exploits are known, such memory corruption issues could be leveraged for privilege escalation or denial of service if exploited.

Summary

The vulnerability in the Linux kernel's mac80211 WiFi component concerns improper handling of RX BA session teardown. Specifically, tearing down an RX BA session can leave the session timer queued on a freed tid_rx structure. During later timer-wheel processing, the timer callback may execute against freed memory, causing use-after-free conditions. The RX BAR handler can dereference tid_rx under RCU before teardown unpublishes it and remain in a read-side critical section while teardown deletes the session timer. This stale handler can rearm the timer after timer_delete_sync() returns but before the RCU callback frees tid_rx. The remediation replaces timer_delete_sync() with timer_shutdown_sync() to ensure rearm attempts are ineffective once teardown starts, preventing use-after-free.

References

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