Linux: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-53086 is a critical-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions e85b0c0a12e967930044608311471b665baa315c, e8206538cbaf4f4068e99a4cb1138690a1e00499, 681fdfe823b4f1036ed50b58b8838c7917ea389c 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 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to e85b0c0a12e967930044608311471b665baa315c or e8206538cbaf4f4068e99a4cb1138690a1e00499 or 681fdfe823b4f1036ed50b58b8838c7917ea389c or c270e2bec3e55a716d25c35341091339457ac883, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.175 or 6.6.141 or 6.12.91 or 6.18.33, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 13ea657806cf73b379a0109f7042182f47c351a7 up to, but not including, e85b0c0a12e967930044608311471b665baa315c; 13ea657806cf73b379a0109f7042182f47c351a7 up to, but not including, e8206538cbaf4f4068e99a4cb1138690a1e00499; 13ea657806cf73b379a0109f7042182f47c351a7 up to, but not including, 681fdfe823b4f1036ed50b58b8838c7917ea389c; 13ea657806cf73b379a0109f7042182f47c351a7 up to, but not including, c270e2bec3e55a716d25c35341091339457ac883; 13ea657806cf73b379a0109f7042182f47c351a7 up to, but not including, 7ce1c26aac3b318886a57425f64b522da7389153; 13ea657806cf73b379a0109f7042182f47c351a7 up to, but not including, 5393b2b5bee2ac51a0043dc7f4ac3475f053d08d; 4.2 | e85b0c0a12e967930044608311471b665baa315c, e8206538cbaf4f4068e99a4cb1138690a1e00499, 681fdfe823b4f1036ed50b58b8838c7917ea389c, c270e2bec3e55a716d25c35341091339457ac883, 7ce1c26aac3b318886a57425f64b522da7389153, 5393b2b5bee2ac51a0043dc7f4ac3475f053d08d |
| Linux | Linux Kernel | 4.2 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 | 6.1.175, 6.6.141, 6.12.91, 6.18.33, 7.0.10 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- 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:N/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: net: bcmgenet: fix racing timeout handler The bcmgenet_timeout handler tries to take down all tx queues when a single queue times out. This is over zealous and causes many race conditions with queues that are still chugging along. Instead lets only restart the timed out queue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization
The 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.
How developers prevent this class of flaw
- In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Use thread-safe capabilities such as the data access abstraction in Spring.
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/5393b2b5bee2ac51a0043dc7f4ac3475f053d08d
- git.kernel.org/stable/c/681fdfe823b4f1036ed50b58b8838c7917ea389c
- git.kernel.org/stable/c/7ce1c26aac3b318886a57425f64b522da7389153
- git.kernel.org/stable/c/c270e2bec3e55a716d25c35341091339457ac883
- git.kernel.org/stable/c/e8206538cbaf4f4068e99a4cb1138690a1e00499
- git.kernel.org/stable/c/e85b0c0a12e967930044608311471b665baa315c
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 7.5 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.1 High severity
- 7.8 High severity
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