CVE-2026-63945
HIGHBluetooth: ISO: serialize iso_sock_clear_timer with socket lock
Blast Radius
KernelReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐧Linux | Kernel | ≥ 6.0.0&&< 6.1.176 | 6.1.176 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 6.1.176 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-63945 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-63945 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-63945. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-63945 in your dependencies?
O3 detects CVE-2026-63945 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.