CyberSecBulletin
CVE-2026-31548NVD status: Modified

Linux: Concurrent Execution using Shared Resource with Improper Synchronization

Published Updated By the CyberSecBulletin desk

CVE-2026-31548 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 28d3551f8d8cb3aec7497894d94150fe84d20e5e, 37e776e2e0a523731e2470dce6d563f0e8632a40, d32c07ef1880fe20cf4ab223dbfedc9c0b2816aa 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 0.1% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 28d3551f8d8cb3aec7497894d94150fe84d20e5e or 37e776e2e0a523731e2470dce6d563f0e8632a40 or d32c07ef1880fe20cf4ab223dbfedc9c0b2816aa or a1b7a843f12a0c3e9d3a2ca607ce451916ef42cf, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.1.167 or 6.6.130 or 6.12.78 or 6.18.20, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux9bb7e0f24e7e7d00daa1219b14539e2e602649b2 up to, but not including, 28d3551f8d8cb3aec7497894d94150fe84d20e5e; 9bb7e0f24e7e7d00daa1219b14539e2e602649b2 up to, but not including, 37e776e2e0a523731e2470dce6d563f0e8632a40; 9bb7e0f24e7e7d00daa1219b14539e2e602649b2 up to, but not including, d32c07ef1880fe20cf4ab223dbfedc9c0b2816aa; 9bb7e0f24e7e7d00daa1219b14539e2e602649b2 up to, but not including, a1b7a843f12a0c3e9d3a2ca607ce451916ef42cf; 9bb7e0f24e7e7d00daa1219b14539e2e602649b2 up to, but not including, 72b7ea786b8e570ae11149e9089859a4a8634a13; 9bb7e0f24e7e7d00daa1219b14539e2e602649b2 up to, but not including, 6dccbc9f3e1d38565dff7730d2b7d1e8b16c9b09; 5.028d3551f8d8cb3aec7497894d94150fe84d20e5e, 37e776e2e0a523731e2470dce6d563f0e8632a40, d32c07ef1880fe20cf4ab223dbfedc9c0b2816aa, a1b7a843f12a0c3e9d3a2ca607ce451916ef42cf, 72b7ea786b8e570ae11149e9089859a4a8634a13, 6dccbc9f3e1d38565dff7730d2b7d1e8b16c9b09
LinuxLinux Kernel5.0.1 up to, but not including, 6.1.167; 6.2 up to, but not including, 6.6.130; 6.7 up to, but not including, 6.12.78; 6.13 up to, but not including, 6.18.20; 6.19 up to, but not including, 6.19.10; 5.0; 7.06.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10

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
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
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:L/AC:L/PR:L/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: wifi: cfg80211: cancel pmsr_free_wk in cfg80211_pmsr_wdev_down When the nl80211 socket that originated a PMSR request is closed, cfg80211_release_pmsr() sets the request's nl_portid to zero and schedules pmsr_free_wk to process the abort asynchronously. If the interface is concurrently torn down before that work runs, cfg80211_pmsr_wdev_down() calls cfg80211_pmsr_process_abort() directly. However, the already- scheduled pmsr_free_wk work item remains pending and may run after the interface has been removed from the driver. This could cause the driver's abort_pmsr callback to operate on a torn-down interface, leading to undefined behavior and potential crashes. Cancel pmsr_free_wk synchronously in cfg80211_pmsr_wdev_down() before calling cfg80211_pmsr_process_abort(). This ensures any pending or in-progress work is drained before interface teardown proceeds, preventing the work from invoking the driver abort callback after the interface is gone.

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).

More Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities (CWE-362)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities

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