CVE-2026-63945: Linux kernel · Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa, bc08c15746f25f41dd0508b25780d1e84acbb2ef, 996c2104d0726a8fe584f85b3d6327197374a348 +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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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.
References
- git.kernel.org/stable/c/d9cbf7144ec589a3f0cc91f74a1a1af2d2b14afa (opens in a new tab)
- git.kernel.org/stable/c/35f68f36d9883d56dec21cf85f7556d4657fc393 (opens in a new tab)
- git.kernel.org/stable/c/996c2104d0726a8fe584f85b3d6327197374a348 (opens in a new tab)
- git.kernel.org/stable/c/bc08c15746f25f41dd0508b25780d1e84acbb2ef (opens in a new tab)
- git.kernel.org/stable/c/51cb9dcfdf9a1bccf312ab2ae4b62db629f7dcd5 (opens in a new tab)
- git.kernel.org/stable/c/4b5f8e608749b7e8fa386c6e4301cf9272595859 (opens in a new tab)