---
cve: "CVE-2026-63945"
severity: "HIGH"
cvss: 7.8
epss: "0.2%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-19 16:17:13"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T04:39:07+02:00"
---

# CVE-2026-63945

> 7.8 HIGH

## Beschreibung

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_clear_timer()
      if (conn != NULL) ...      lock_sock(sk)
                                   iso_chan_del()
                                   iso_pi(sk)->conn = NULL
      cancel_delayed_work(conn)  /* NULL deref or UAF */

iso_pi(sk)->conn is not stable across the unlock window, causing a
NULL pointer dereference or use-after-free.

Serialize iso_sock_clear_timer() with the socket lock by moving it
inside lock_sock()/release_sock(), matching the pattern used in
iso_conn_del() and all other call sites.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 6.1.176
- Kernel ≥ 6.6.143
- Kernel ≥ 6.12.93
- Kernel ≥ 6.18.35
- Kernel ≥ 7.0.12

## Referenzen

- <https://git.kernel.org/stable/c/d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa>
- <https://git.kernel.org/stable/c/35f68f36d9883d56dec21cf85f7556d4657fc393>
- <https://git.kernel.org/stable/c/996c2104d0726a8fe584f85b3d6327197374a348>
- <https://git.kernel.org/stable/c/bc08c15746f25f41dd0508b25780d1e84acbb2ef>
- <https://git.kernel.org/stable/c/51cb9dcfdf9a1bccf312ab2ae4b62db629f7dcd5>
- <https://git.kernel.org/stable/c/4b5f8e608749b7e8fa386c6e4301cf9272595859>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-63945) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_