Linux: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-64077 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 b37e27f5d5cbb7723644fdf089e28a216d6093ed, 6fe4c808b6cdb405ed64ea6e740d557bba3d7745, f34e5a674afe743d1af80684d64b511f40a5c35d 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 0.14% 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 b37e27f5d5cbb7723644fdf089e28a216d6093ed or 6fe4c808b6cdb405ed64ea6e740d557bba3d7745 or f34e5a674afe743d1af80684d64b511f40a5c35d or 739d5dac7b2da44a756aa4d758ee3f1ccf5a27f1, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.34 or 7.0.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 87663c39f898b18905499126548da61450628682 up to, but not including, b37e27f5d5cbb7723644fdf089e28a216d6093ed; 87663c39f898b18905499126548da61450628682 up to, but not including, 6fe4c808b6cdb405ed64ea6e740d557bba3d7745; 87663c39f898b18905499126548da61450628682 up to, but not including, f34e5a674afe743d1af80684d64b511f40a5c35d; 87663c39f898b18905499126548da61450628682 up to, but not including, 739d5dac7b2da44a756aa4d758ee3f1ccf5a27f1; 87663c39f898b18905499126548da61450628682 up to, but not including, ef395579a7631a06d61969fc712eb80402231b89; 87663c39f898b18905499126548da61450628682 up to, but not including, b7f0544d86d439cb946515d2ef6a0a75e8626710; 5.15 | b37e27f5d5cbb7723644fdf089e28a216d6093ed, 6fe4c808b6cdb405ed64ea6e740d557bba3d7745, f34e5a674afe743d1af80684d64b511f40a5c35d, 739d5dac7b2da44a756aa4d758ee3f1ccf5a27f1, ef395579a7631a06d61969fc712eb80402231b89, b7f0544d86d439cb946515d2ef6a0a75e8626710 |
| Linux | Linux Kernel | 5.15 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.1 | 6.18.34, 7.0.11 |
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: netfilter: ebtables: move to two-stage removal scheme Like previous patches for x_tables, follow same pattern in ebtables. We can't reuse xt helpers: ebt_table struct layout is incompatible. table->ops assignment is now done while still holding the ebt mutex to make sure we never expose partially-filled table struct.
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: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
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