Linux: Use After Free
CVE-2026-46111 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions d41093723e47255d7d74df86e2736711c1b8486e, 6823f730bf195fc296d9edd09e2ca94bc1ff5584, 1750a2df0eab61dc421a7afae74abdd239a44b85 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d41093723e47255d7d74df86e2736711c1b8486e or 6823f730bf195fc296d9edd09e2ca94bc1ff5584 or 1750a2df0eab61dc421a7afae74abdd239a44b85 or dc34f8d8240f25dd137dc2758ebbcc75e3779142, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.140 or 6.12.90 or 6.18.32 or 7.0.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | eca0ae4aea66914515e5e3098ea051b518ee5316 up to, but not including, d41093723e47255d7d74df86e2736711c1b8486e; eca0ae4aea66914515e5e3098ea051b518ee5316 up to, but not including, 6823f730bf195fc296d9edd09e2ca94bc1ff5584; eca0ae4aea66914515e5e3098ea051b518ee5316 up to, but not including, 1750a2df0eab61dc421a7afae74abdd239a44b85; eca0ae4aea66914515e5e3098ea051b518ee5316 up to, but not including, dc34f8d8240f25dd137dc2758ebbcc75e3779142; eca0ae4aea66914515e5e3098ea051b518ee5316 up to, but not including, f8eaf92c57ad99358dd372580d5ff87623343a72; eca0ae4aea66914515e5e3098ea051b518ee5316 up to, but not including, 0beddb0c380bed5f5b8e61ddbe14635bb73d0b41; 6.0 | d41093723e47255d7d74df86e2736711c1b8486e, 6823f730bf195fc296d9edd09e2ca94bc1ff5584, 1750a2df0eab61dc421a7afae74abdd239a44b85, dc34f8d8240f25dd137dc2758ebbcc75e3779142, f8eaf92c57ad99358dd372580d5ff87623343a72, 0beddb0c380bed5f5b8e61ddbe14635bb73d0b41 |
| Linux | Linux Kernel | 6.0 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.90; 6.13 up to, but not including, 6.18.32; 6.19 up to, but not including, 7.0.7; 7.1 | 6.6.140, 6.12.90, 6.18.32, 7.0.7 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.
Official 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().
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/0beddb0c380bed5f5b8e61ddbe14635bb73d0b41
- git.kernel.org/stable/c/1750a2df0eab61dc421a7afae74abdd239a44b85
- git.kernel.org/stable/c/6823f730bf195fc296d9edd09e2ca94bc1ff5584
- git.kernel.org/stable/c/dc34f8d8240f25dd137dc2758ebbcc75e3779142
- git.kernel.org/stable/c/f8eaf92c57ad99358dd372580d5ff87623343a72
Other references
Recent Use After Free vulnerabilities
- 8.3 High severity
- 8.8 High severity
- 8.3 High severity
- 8.3 High severity
- 8.8 High severity
- 7.5 High severity
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