In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix UAF in iso_recv_frame iso_recv_frame reads conn->sk under… (CVE-2026-63946)
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix UAF in iso_recv_frame iso_recv_frame reads conn->sk under iso_conn_lock but releases the lock before using sk, with no reference held. A concurrent iso_sock_kill() can free sk in that window, causing use-after-free on sk->sk_state and sock_queue_rcv_skb(). Fix by replacing the bare pointer read with iso_sock_hold(conn), which calls sock_hold() while the spinlock is held, atomically elevating the refcount before the lock drops. Add a drop_put label so sock_put() is called on all exit paths where the hold succeeded.
AI Analysis
Technical Summary
CVE-2026-63946 is a use-after-free vulnerability in the Linux kernel Bluetooth ISO subsystem. The iso_recv_frame function reads the socket pointer conn->sk under a lock but releases the lock before using the socket without holding a reference. This allows a concurrent iso_sock_kill() call to free the socket, leading to use-after-free on socket state and receive queue functions. The vulnerability was fixed by replacing the bare pointer read with a call to iso_sock_hold(conn), which atomically increments the socket reference count while the lock is held, preventing the socket from being freed prematurely.
Potential Impact
This vulnerability could lead to use-after-free conditions in the Bluetooth ISO code path of the Linux kernel, potentially causing kernel crashes or undefined behavior. No known exploits in the wild have been reported. The impact is limited to systems running vulnerable Linux kernel versions with Bluetooth ISO support.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by properly managing socket references in the iso_recv_frame function. Users should apply the official Linux kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor or Linux kernel advisory for the current remediation guidance.
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix UAF in iso_recv_frame iso_recv_frame reads conn->sk under… (CVE-2026-63946)
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix UAF in iso_recv_frame iso_recv_frame reads conn->sk under iso_conn_lock but releases the lock before using sk, with no reference held. A concurrent iso_sock_kill() can free sk in that window, causing use-after-free on sk->sk_state and sock_queue_rcv_skb(). Fix by replacing the bare pointer read with iso_sock_hold(conn), which calls sock_hold() while the spinlock is held, atomically elevating the refcount before the lock drops. Add a drop_put label so sock_put() is called on all exit paths where the hold succeeded.
CVSS v3.1
Score 8.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-63946 is a use-after-free vulnerability in the Linux kernel Bluetooth ISO subsystem. The iso_recv_frame function reads the socket pointer conn->sk under a lock but releases the lock before using the socket without holding a reference. This allows a concurrent iso_sock_kill() call to free the socket, leading to use-after-free on socket state and receive queue functions. The vulnerability was fixed by replacing the bare pointer read with a call to iso_sock_hold(conn), which atomically increments the socket reference count while the lock is held, preventing the socket from being freed prematurely.
Potential Impact
This vulnerability could lead to use-after-free conditions in the Bluetooth ISO code path of the Linux kernel, potentially causing kernel crashes or undefined behavior. No known exploits in the wild have been reported. The impact is limited to systems running vulnerable Linux kernel versions with Bluetooth ISO support.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by properly managing socket references in the iso_recv_frame function. Users should apply the official Linux kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor or Linux kernel advisory for the current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-9g79-vcq4-5rfr
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-63946"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a5d27aa2a4a8d598912ebbc
Added to database: 07/19/2026, 19:38:18 UTC
Last enriched: 07/19/2026, 20:05:27 UTC
Last updated: 09/02/2026, 22:52:13 UTC
Views: 65
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