CyberSecBulletin
CVE-2026-98130NVD status: Analyzed

Linux: Concurrent Execution using Shared Resource with Improper Synchronization

Published Updated By the CyberSecBulletin desk

CVE-2026-98130 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Linux, with a CVSS 3.1 base score of 8.1 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 cbf2df9aac4202f9fb0b361a7fe8c79b29fad92c, 3205a20f837f5b1f009427ac3d9f706bf8a6fbec, 755d70ca845fd9b87c7b338ae6ae832b08cd0005 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 0.45% 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 cbf2df9aac4202f9fb0b361a7fe8c79b29fad92c or 3205a20f837f5b1f009427ac3d9f706bf8a6fbec or 755d70ca845fd9b87c7b338ae6ae832b08cd0005 or 09e7f9290d63178f56095d5c18fb9f9470153db5, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.20 or 5.5 or 5.7 or 5.10.271, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, cbf2df9aac4202f9fb0b361a7fe8c79b29fad92c; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, 3205a20f837f5b1f009427ac3d9f706bf8a6fbec; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, 755d70ca845fd9b87c7b338ae6ae832b08cd0005; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, 09e7f9290d63178f56095d5c18fb9f9470153db5; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, e42ba56281ca3ae2dcb3558bebee9a1c9a4831d9; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, 00b841bac10230c557be6b38efc48508198fe23e; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, 3d698d1e6c8bc41e3e1707777a016f1bdd07842d; 20a785aa52c82246055a089e55df9dac47d67da1 up to, but not including, 2188569e7e1b0bc3f3b557dc97ab7a02befc11c8; and 7 more rangescbf2df9aac4202f9fb0b361a7fe8c79b29fad92c, 3205a20f837f5b1f009427ac3d9f706bf8a6fbec, 755d70ca845fd9b87c7b338ae6ae832b08cd0005, 09e7f9290d63178f56095d5c18fb9f9470153db5, e42ba56281ca3ae2dcb3558bebee9a1c9a4831d9, 00b841bac10230c557be6b38efc48508198fe23e
LinuxLinux Kernel4.19.126 up to, but not including, 4.20; 5.4.44 up to, but not including, 5.5; 5.6.16 up to, but not including, 5.7; 5.7.1 up to, but not including, 5.10.271; 5.11 up to, but not including, 5.15.222; 5.16 up to, but not including, 6.1.189; 6.2 up to, but not including, 6.6.158; 6.7 up to, but not including, 6.12.111; and 4 more ranges4.20, 5.5, 5.7, 5.10.271, 5.15.222, 6.1.189

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
HighSuccess depends on conditions outside the attacker's control.
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:H/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: sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START The SCTP_CMD_TIMER_START handler checks timer_pending() before calling timer_reduce(). The timer can expire and detach between these operations, causing timer_reduce() to rearm the timer without taking the association reference required for the newly armed timer. The timer callback later unconditionally drops its association reference, which can leave the association reference count unbalanced and result in use-after-free during association teardown. Use the return value of timer_reduce() to determine whether the timer was actually armed. Take the association reference only when timer_reduce() successfully starts a new timer, closing the race between checking the timer state and rearming it. This issue was reported by Nico Yip (@_cyeaa_) working with TrendAI Zero Day Initiative.

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. 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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