Linux: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-46327 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 175ac0a6115400278d3900f5a04a58b17b3f6cd0, 7a3385e97af2b6f485fef11e82d8c29adee4be93, d809a36692ee1394cac85ce6ba7cf8ea58da5812 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.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 175ac0a6115400278d3900f5a04a58b17b3f6cd0 or 7a3385e97af2b6f485fef11e82d8c29adee4be93 or d809a36692ee1394cac85ce6ba7cf8ea58da5812 or 24c405fdbe215c45e57bba672cc42859038491ee, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.75 or 6.18.14 or 6.19.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | f9c1bdf24615303d48a2d0fd629c88f3189563aa up to, but not including, 175ac0a6115400278d3900f5a04a58b17b3f6cd0; 37f53a2c60d03743e0eacf7a0c01c279776fef4e up to, but not including, 7a3385e97af2b6f485fef11e82d8c29adee4be93; 37f53a2c60d03743e0eacf7a0c01c279776fef4e up to, but not including, d809a36692ee1394cac85ce6ba7cf8ea58da5812; 37f53a2c60d03743e0eacf7a0c01c279776fef4e up to, but not including, 24c405fdbe215c45e57bba672cc42859038491ee; d19bc1b4dd5f322980b1f05f79b2ea4f0db10920; 6.12.34 up to, but not including, 6.12.75; 6.15.3 up to, but not including, 6.16; 6.16 | 175ac0a6115400278d3900f5a04a58b17b3f6cd0, 7a3385e97af2b6f485fef11e82d8c29adee4be93, d809a36692ee1394cac85ce6ba7cf8ea58da5812, 24c405fdbe215c45e57bba672cc42859038491ee, 6.12.75, 6.16 |
| Linux | Linux Kernel | 6.12.34 up to, but not including, 6.12.75; 6.15.3 up to, but not including, 6.18.14; 6.19 up to, but not including, 6.19.4 | 6.12.75, 6.18.14, 6.19.4 |
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: dm: fix unlocked test for dm_suspended_md The function dm_blk_report_zones tests if the device is suspended with the "dm_suspended_md" call. However, this function is called without holding any locks, so the device may be suspended just after it. Move the call to dm_suspended_md after dm_get_live_table, so that the device can't be suspended after the suspended state was tested.
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
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.