Linux: Improper Locking
CVE-2026-53072 is a high-severity improper locking vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4, 9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e, c7777f534a8018ae4bb1c80d8925af4df588a314 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 0.2% 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 60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4 or 9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e or c7777f534a8018ae4bb1c80d8925af4df588a314 or 6b4d226d01ab7da0d2027a2a1e3a6079152e5065, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.141, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, 60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, 9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, c7777f534a8018ae4bb1c80d8925af4df588a314; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, 6b4d226d01ab7da0d2027a2a1e3a6079152e5065; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, 541d5bf9b5afaf41090b2a3aa7b47f2db2ff801f; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, 385b2d0468a0871fc716c549fa3b0c257c7dbcb3; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, c27224daf0b08efbb2b24ed64b6139b294f5473a; 70c464256310e1c3716099b9d02ece4169272f73 up to, but not including, 5c7209a341ff2ac338b2b0375c34a307b37c9ac2; and 1 more ranges | 60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4, 9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e, c7777f534a8018ae4bb1c80d8925af4df588a314, 6b4d226d01ab7da0d2027a2a1e3a6079152e5065, 541d5bf9b5afaf41090b2a3aa7b47f2db2ff801f, 385b2d0468a0871fc716c549fa3b0c257c7dbcb3 |
| Linux | Linux Kernel | 3.17 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.141; 6.7 up to, but not including, 6.12.91; 6.13 up to, but not including, 6.18.33; 6.19 up to, but not including, 7.0.10 | 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, 6.18.33 |
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
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- 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:A/AC:L/PR:N/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: 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Locking
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
How developers prevent this class of flaw
- Use industry standard APIs to implement locking mechanism.
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/385b2d0468a0871fc716c549fa3b0c257c7dbcb3
- git.kernel.org/stable/c/541d5bf9b5afaf41090b2a3aa7b47f2db2ff801f
- git.kernel.org/stable/c/5c7209a341ff2ac338b2b0375c34a307b37c9ac2
- git.kernel.org/stable/c/60e3f4ff02d1f2d55bfbf2ca32a97285a9771ee4
- git.kernel.org/stable/c/6b4d226d01ab7da0d2027a2a1e3a6079152e5065
- git.kernel.org/stable/c/9d4a6c0f43fc5e4d4f062e8e450e5483eb74176e
- git.kernel.org/stable/c/c27224daf0b08efbb2b24ed64b6139b294f5473a
- git.kernel.org/stable/c/c7777f534a8018ae4bb1c80d8925af4df588a314
Recent Improper Locking vulnerabilities
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
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