Linux: Improper Synchronization
CVE-2026-68103 is a high-severity improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 1050d258c7c56066d2dcaedf8d0ef66364062adc, a609b6278bf3cde17eeee6620091465521e4b02c 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 0.11% 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 1050d258c7c56066d2dcaedf8d0ef66364062adc or a609b6278bf3cde17eeee6620091465521e4b02c, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8949843762631d9d0fc526dfb61a272dca29fc6f up to, but not including, 1050d258c7c56066d2dcaedf8d0ef66364062adc; 8949843762631d9d0fc526dfb61a272dca29fc6f up to, but not including, a609b6278bf3cde17eeee6620091465521e4b02c; 6.16 | 1050d258c7c56066d2dcaedf8d0ef66364062adc, a609b6278bf3cde17eeee6620091465521e4b02c |
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
- NoneNo data is disclosed.
- 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:N/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: reject mapping a reserved doorbell to a new queue When creating an user-queue, the user space provides a doorbell BO handle and an offset within the bo to obtain a doorbell. However current implementation using xa_store_irq() to store a doorbell, which allows a later queue created with the same BO and offset parameters to overwrite an existing queue and doorbell mapping. This can cause problems like misrouting fence IRQ processing to a wrong queue, and mislead the cleanup process of one queue erasing the mapping of another queue. This commit fixes this issue by replacing xa_store_irq with xa_insert_irq, which rejects mapping a reserved doorbell to a newly created queue (cherry picked from commit 6244eae22966350db52faf9c1369d3b2ffc5de4e)
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Synchronization
The product utilizes multiple threads, processes, components, or systems to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.
How developers prevent this class of flaw
- Use industry standard APIs to synchronize your code.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Synchronization vulnerabilities
- 7.8 High severity
- 8.4 High severity
- 7.8 High severity
- 7.5 High severity
- 8.8 High severity
- 8.2 High severity
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