CVE-2026-63946
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk25th 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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In the Linux kernel powerpc/pseries papr-phy-attest, missing validation of cmd.length could lead to buffer overflow. The fix adds length checks and fixes memory leaks on error paths.
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- CVE-2026-80542Unknown
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- CVE-2026-80535Unknown
In the Linux kernel XFS filesystem, during directory tree repair, a self-referential directory may be detected. In such a case, the repair code attempts to lock the same inode twice (double iolock/ilock), leading to a deadlock. The fix detects this corner case and handles it appropriately.
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.

