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Review reviewHigh

CVE-2026-63946

Linux

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...

CVSS
8.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.20
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 8.8

Vulnerability overview

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...

Affected product and versions

Product
Linux
Affected versions
>= ccf74f2390d60a2f9a75ef496d2564abb478f46a < c57ea90f203c8b8b41a474f19a09000d0f841436, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 119fb6f80c44dc1c65d604cf28e64c56bd9b6568, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < b04ec131325baf4ea4577d6c6e6b86cf092e3731, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < c318aa51830a3d2cc1229968fe521441c97356cd, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 1a6b803b00ccdd7666506adbe01ddae1c72d1ca9, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 47f23a259517abbdb8032c057a1e8a6bf3734878, >= 6.0
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available
CVE-2026-63946 — Linux | SECUFOCUS NOW