In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: RFCOMM: serialize security confirmation handling

rfcomm_security_cfm() looks up a session on session_list and then walks
its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown
uses rfcomm_mutex, krfcommd can close and free the same session and DLCs
concurrently:

hci_rx_work krfcommd
----------- ---------
rfcomm_session_get()
rfcomm_lock()
rfcomm_session_close()
rfcomm_dlc_unlink()
rfcomm_session_del()
kfree(s)
rfcomm_unlock()
walk s->dlcs

The callback can then read a freed session list head and touch freed DLCs
while updating their flags or timers.

Serialize the session lookup and DLC traversal in rfcomm_security_cfm()
with rfcomm_mutex. This matches the existing RFCOMM session lifetime
rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()
from tearing the objects down while the callback is using them.

KASAN reported:

BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440
Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89
Workqueue: hci0 hci_rx_work
Call Trace:
rfcomm_security_cfm+0x41c/0x440
hci_encrypt_cfm+0x139/0x590
hci_encrypt_change_evt+0x37b/0xc40
hci_event_packet+0x71b/0xb20
hci_rx_work+0x293/0x730
Allocated by task 69:
rfcomm_session_add+0x9e/0x2f0
rfcomm_run+0x44b/0x41e0
Freed by task 69:
kfree+0x131/0x3c0
rfcomm_session_del+0x188/0x220
rfcomm_run+0x1985/0x41e0

No CVSS v4.0

Attack Vector Adjacent Network

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
08c30aca9e698faddebd34f81e1196295f9dc063 affected < 1b7841ffad08e911e8c4b9470f3fa08423568940
08c30aca9e698faddebd34f81e1196295f9dc063 affected < 946d76db77ee5f922968ce558629ae47b381e3fc
08c30aca9e698faddebd34f81e1196295f9dc063 affected < fbf7961964a6e93360179f64712320ae9a1e9577
08c30aca9e698faddebd34f81e1196295f9dc063 affected < 759c185d0bbdb131357408f50b8735e04ed3caff
Linux Linux affected
Version Status Constraints
3.10 affected —
0 unaffected < 3.10
6.12.109 unaffected ≤ 6.12.*
6.18.50 unaffected ≤ 6.18.*
7.2.4 unaffected ≤ 7.2.*
7.3-rc1 unaffected ≤ *

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940 cve-icon cve-icon cve-icon
https://git.kernel.org/stable/c/759c185d0bbdb131357408f50b8735e04ed3caff cve-icon cve-icon cve-icon
https://git.kernel.org/stable/c/946d76db77ee5f922968ce558629ae47b381e3fc cve-icon cve-icon cve-icon
https://git.kernel.org/stable/c/fbf7961964a6e93360179f64712320ae9a1e9577 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-89569 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-89569 cve-icon
History

Sat, 12 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-825
References
Metrics threat_severity

None

 cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important

Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: serialize security confirmation handling rfcomm_security_cfm() looks up a session on session_list and then walks its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown uses rfcomm_mutex, krfcommd can close and free the same session and DLCs concurrently: hci_rx_work krfcommd ----------- --------- rfcomm_session_get() rfcomm_lock() rfcomm_session_close() rfcomm_dlc_unlink() rfcomm_session_del() kfree(s) rfcomm_unlock() walk s->dlcs The callback can then read a freed session list head and touch freed DLCs while updating their flags or timers. Serialize the session lookup and DLC traversal in rfcomm_security_cfm() with rfcomm_mutex. This matches the existing RFCOMM session lifetime rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink() from tearing the objects down while the callback is using them. KASAN reported: BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440 Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89 Workqueue: hci0 hci_rx_work Call Trace: rfcomm_security_cfm+0x41c/0x440 hci_encrypt_cfm+0x139/0x590 hci_encrypt_change_evt+0x37b/0xc40 hci_event_packet+0x71b/0xb20 hci_rx_work+0x293/0x730 Allocated by task 69: rfcomm_session_add+0x9e/0x2f0 rfcomm_run+0x44b/0x41e0 Freed by task 69: kfree+0x131/0x3c0 rfcomm_session_del+0x188/0x220 rfcomm_run+0x1985/0x41e0
Title Bluetooth: RFCOMM: serialize security confirmation handling
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-11T19:44:38.838Z

Reserved: 2026-09-11T19:38:34.726Z

Link: CVE-2026-89569

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T20:19:40.920

Modified: 2026-09-11T20:19:40.920

Link: CVE-2026-89569

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-11T19:44:38Z

Links: CVE-2026-89569 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses