CVE Catalog

CVE-2026-63946

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.33%

25th percentile - higher than 25% of all known CVEs

Summary

A Use-After-Free (UAF) vulnerability was found in the Linux kernel's Bluetooth ISO stack in the iso_recv_frame function. It reads the socket pointer under a lock but uses it after releasing the lock, allowing a concurrent iso_sock_kill() to free the memory.

Risk Assessment

An attacker can remotely trigger a kernel panic or potentially escalate privileges by exploiting the UAF bug in the Bluetooth stack.

Recommendation

Apply the Linux kernel patch for CVE-2026-63946 immediately, which adds atomic socket reference counting before use.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS