CVE-2026-53072: Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER
Vulnerability summary
CVE-2026-53072 is a high (CVSS 8.8) Improper Locking vulnerability in linux. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.3% of scored vulnerabilities.
Not severe (CVSS 8.8, adjacent network); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 56 · Related 54Timeline
- 24-06-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER When protocol sets HCI_PROTO_DEFER, hci_conn_request_evt() calls hci_connect_cfm(conn) without hdev->lock. Generally hci_connect_cfm() assumes it is held, and if conn is deleted concurrently -> UAF. Only SCO and ISO set HCI_PROTO_DEFER and only for defer setup listen, and HCI_EV_CONN_REQUEST is not generated for ISO. In the non-deferred listening socket code paths, hci_connect_cfm(conn) is called with hdev->lock held. Fix by holding the lock.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.20%
Chance of exploitation in the next 30 days
Percentile
9%
Versus all other CVEs
30-day change
Decrease -0.12 pp
From 0.32% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-667Improper LockingThe product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
- CWE-362Concurrent Execution using Shared Resource with Improper SynchronizationThe product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Affected systems
Known conditions: adjacent network, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu166 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 70c464256310e1c3716099b9d02ece4169272f73, < 60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4 | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < 9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < c7777f534a8018ae4bb1c80d8925af4df588a314 | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < 6b4d226d01ab7da0d2027a2a1e3a6079152e5065 | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < 541d5bf9b5afaf41090b2a3aa7b47f2db2ff801f | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < 385b2d0468a0871fc716c549fa3b0c257c7dbcb3 | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < c27224daf0b08efbb2b24ed64b6139b294f5473a | ≥ 70c464256310e1c3716099b9d02ece4169272f73, < 5c7209a341ff2ac338b2b0375c34a307b37c9ac2 | 3.17
- linux_kernel≥ 3.17, < 5.10.258 | ≥ 5.11, < 5.15.209 | ≥ 5.16, < 6.1.175 | ≥ 6.2, < 6.6.141 | ≥ 6.7, < 6.12.91 | ≥ 6.13, < 6.18.33 | ≥ 6.19, < 7.0.10
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.10-1
3 vendors · 169 products
