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VulnerabilityPublished Updated

CVE-2026-46111: Linux kernel · Bluetooth: hci_conn: fix potential UAF in create_big_sync

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in f8eaf92c57ad99358dd372580d5ff87623343a72 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% 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 f8eaf92c57ad99358dd372580d5ff87623343a72, dc34f8d8240f25dd137dc2758ebbcc75e3779142, d41093723e47255d7d74df86e2736711c1b8486e +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ eca0ae4aea66914515e5e3098ea051b518ee5316, < f8eaf92c57ad99358dd372580d5ff87623343a72
Fixed in
  • f8eaf92c57ad99358dd372580d5ff87623343a72
LinuxLinuxAffected
  • ≥ eca0ae4aea66914515e5e3098ea051b518ee5316, < dc34f8d8240f25dd137dc2758ebbcc75e3779142
Fixed in
  • dc34f8d8240f25dd137dc2758ebbcc75e3779142
LinuxLinuxAffected
  • ≥ eca0ae4aea66914515e5e3098ea051b518ee5316, < d41093723e47255d7d74df86e2736711c1b8486e
Fixed in
  • d41093723e47255d7d74df86e2736711c1b8486e
LinuxLinuxAffected
  • ≥ eca0ae4aea66914515e5e3098ea051b518ee5316, < 6823f730bf195fc296d9edd09e2ca94bc1ff5584
Fixed in
  • 6823f730bf195fc296d9edd09e2ca94bc1ff5584
LinuxLinuxAffected
  • ≥ eca0ae4aea66914515e5e3098ea051b518ee5316, < 1750a2df0eab61dc421a7afae74abdd239a44b85
Fixed in
  • 1750a2df0eab61dc421a7afae74abdd239a44b85
LinuxLinuxAffected
  • ≥ eca0ae4aea66914515e5e3098ea051b518ee5316, < 0beddb0c380bed5f5b8e61ddbe14635bb73d0b41
Fixed in
  • 0beddb0c380bed5f5b8e61ddbe14635bb73d0b41

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: fix potential UAF in create_big_sync Add hci_conn_valid() check in create_big_sync() to detect stale connections before proceeding with BIG creation. Handle the resulting -ECANCELED in create_big_complete() and re-validate the connection under hci_dev_lock() before dereferencing, matching the pattern used by create_le_conn_complete() and create_pa_complete(). Keep the hci_conn object alive across the async boundary by taking a reference via hci_conn_get() when queueing create_big_sync(), and dropping it in the completion callback. The refcount and the lock are complementary: the refcount keeps the object allocated, while hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on hdev->conn_hash, as required by hci_conn_del(). hci_conn_put() is called outside hci_dev_unlock() so the final put (which resolves to kfree() via bt_link_release) does not run under hdev->lock, though the release path would be safe either way. Without this, create_big_complete() would unconditionally dereference the conn pointer on error, causing a use-after-free via hci_connect_cfm() and hci_conn_del().

References

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