VulnerabilityPublished 25 Sep 2026Updated 19 Oct 2026

CVE-2026-97977: Linux kernel · Bluetooth: btusb: Fix UAF of btusb_data by rx_work

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in fc654a72a8d979db15e2773a481e931abaf5a9e8 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in fc654a72a8d979db15e2773a481e931abaf5a9e8, fa391adb9c755515a89993634745e9079e5ef37c, 5242050195a711e9cd6a9935f689ab6656b94a91 +3

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 800fe5ec302e1ebbf5e3f891f886deecd49c7132, < fc654a72a8d979db15e2773a481e931abaf5a9e8	Fixed in fc654a72a8d979db15e2773a481e931abaf5a9e8
LinuxLinux	Affected ≥ 800fe5ec302e1ebbf5e3f891f886deecd49c7132, < fa391adb9c755515a89993634745e9079e5ef37c	Fixed in fa391adb9c755515a89993634745e9079e5ef37c
LinuxLinux	Affected ≥ 800fe5ec302e1ebbf5e3f891f886deecd49c7132, < 5242050195a711e9cd6a9935f689ab6656b94a91	Fixed in 5242050195a711e9cd6a9935f689ab6656b94a91
LinuxLinux	Affected ≥ 800fe5ec302e1ebbf5e3f891f886deecd49c7132, < 472d005622525b7be155cac99dde2252b0163bd1	Fixed in 472d005622525b7be155cac99dde2252b0163bd1
LinuxLinux	Affected ≥ 800fe5ec302e1ebbf5e3f891f886deecd49c7132, < 93b59937bda3fffc6386c79f5544a39bc680c8e8	Fixed in 93b59937bda3fffc6386c79f5544a39bc680c8e8
LinuxLinux	Affected ≥ 800fe5ec302e1ebbf5e3f891f886deecd49c7132, < 1c12c3117639e78940959d956519c758c57d0849	Fixed in 1c12c3117639e78940959d956519c758c57d0849

AI-suggested

A fix is available and has been applied in the Linux kernel. Users should update to a kernel version that includes the commit fixes identified by the provided hashes. No additional mitigation steps are indicated or necessary beyond applying the official patch.

Description

A use-after-free (UAF) vulnerability was identified and fixed in the Linux kernel's Bluetooth USB driver (btusb). The issue arises because btusb_close() and btusb_flush() cancel a delayed work item asynchronously, allowing the work to continue running on another CPU after the data structure has been freed. This leads to dereferencing freed memory in btusb_rx_work(). The fix involves using a synchronous cancel function and adjusting the order of operations to prevent race conditions.

Impact

The vulnerability allows a use-after-free condition in the Bluetooth USB driver, which can lead to kernel memory corruption. This could potentially cause system instability or crashes. There is no indication of known exploits in the wild or direct evidence of privilege escalation or code execution from this flaw in the provided data.

Summary

CVE-2026-97977 addresses a use-after-free vulnerability in the Linux kernel Bluetooth USB driver (btusb). The flaw occurs when btusb_close() and btusb_flush() cancel the rx_work asynchronously, but if btusb_rx_work() is already running on another CPU, it continues executing after the associated btusb_data structure has been freed by btusb_disconnect(). This results in a use-after-free condition when btusb_rx_work() accesses freed memory. The patch replaces cancel_delayed_work() with cancel_delayed_work_sync() to ensure the work is fully stopped before freeing data, and reorders operations in btusb_close() to avoid race conditions with URB completions.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 13:09 UTC

Technical details

References

Community reviews

Related threats