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Review reviewHigh

CVE-2026-63945

Linux

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_...

CVSS
7.8
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 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock iso_sock_close() calls iso_sock_clear_timer() before acquiring lock_sock(sk). iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the socket lock held: if (!iso_pi(sk)->conn) return; cancel_delayed_work(&iso_pi(sk)->conn->timeout_work); Concurrently, iso_conn_del() executes under lock_sock(sk) and calls iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in the final reference to the connection being dropped: CPU0 CPU1 ---- ---- iso_sock_...

Affected product and versions

Product
Linux
Affected versions
>= ccf74f2390d60a2f9a75ef496d2564abb478f46a < d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 35f68f36d9883d56dec21cf85f7556d4657fc393, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 996c2104d0726a8fe584f85b3d6327197374a348, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < bc08c15746f25f41dd0508b25780d1e84acbb2ef, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 51cb9dcfdf9a1bccf312ab2ae4b62db629f7dcd5, >= ccf74f2390d60a2f9a75ef496d2564abb478f46a < 4b5f8e608749b7e8fa386c6e4301cf9272595859, >= 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available
CVE-2026-63945 — Linux | SECUFOCUS NOW