# CVE-2026-98737: Bluetooth: hci_sync: Fix inquiry cache use-after-free

CVE-2026-98737 is fixed in 12 products on 1 platform, first by DEBIAN-CVE-2026-98737, released October 19, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-98737
- Priority: High
- CVSS: 7.1 (Important)
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 18, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98737

## Description

In the Linux kernel, the following vulnerability has been resolved:  Bluetooth: hci_sync: Fix inquiry cache use-after-free  The sync command worker holds hdev->req_lock, but inquiry-cache updates and flushes use hdev->lock. Both hci_acl_create_conn_sync() and hci_stop_discovery_sync() look up entries and read their fields without taking hdev->lock.  After either lookup returns, a concurrent HCIINQUIRY ioctl can acquire hdev->lock and flush the cache, freeing the entry. The worker then reads the freed entry while preparing a create-connection or remote-name-cancel command. The list traversal also races with cache updates and removal.  KASAN reported these accesses:    BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5f1/0x650   Workqueue: hci0 hci_cmd_sync_work   Call Trace:    hci_acl_create_conn_sync+0x5f1/0x650    hci_cmd_sync_work+0x13c/0x290    Allocated by task 90:    hci_inquiry_cache_update+0x3e6/0x7d0    hci_inquiry_result_evt+0x3cb/0x560    Freed by task 93:    hci_inquiry_cache_flush+0x111/0x2b0    hci_inquiry+0x2f2/0x780    hci_sock_ioctl+0x269/0x5f0    BUG: KASAN: slab-use-after-free in hci_stop_discovery_sync+0x3b1/0x3c0   Workqueue: hci0 hci_cmd_sync_work   Call Trace:    hci_stop_discovery_sync+0x3b1/0x3c0    hci_cmd_sync_work+0x173/0x300    Allocated by task 86:    hci_inquiry_cache_update+0x483/0x940    hci_inquiry_result_evt+0x3cb/0x560    Freed by task 91:    hci_inquiry_cache_flush+0x13e/0x2f0    hci_inquiry+0x2f2/0x780    hci_sock_ioctl+0x269/0x5f0  Hold hdev->lock across each lookup and all reads from its result. Copy the remote address before unlocking so discovery cancellation does not retain a cache entry pointer. Release the lock before sending synchronous HCI commands, since their completion handlers may need the same lock.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-default sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.90.1.150700.17.51.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-SLE15-SP7_Update_24 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-source sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.90.1 | [SUSE-SU-2026:5091-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-5091-1.md) | Nov 7, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-98737](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98737.md) | Oct 19, 2026 |
| Linux | linux Debian 14 | 7.2.10-1 | [DEBIAN-CVE-2026-98737](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98737.md) | Oct 19, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.113-1~deb12u1 | [DEBIAN-CVE-2026-98737](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98737.md) | Oct 19, 2026 |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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