CVE-2026-31532
Description
A flaw was found in the Linux kernel's Controller Area Network (CAN) raw socket implementation. A use-after-free vulnerability can occur due to a timing window during the unregistration of CAN receive filters, allowing a freed memory region to be accessed. This could lead to system instability or a denial of service (DoS).
Statement
A use-after-free flaw in the Linux kernel CAN raw socket implementation can occur when raw_release() frees the per-CPU ro->uniq storage before RCU-deferred receive callbacks have fully drained. A local attacker able to create raw CAN sockets and trigger CAN receive activity could race socket teardown with raw_rcv() and cause a kernel crash. The likely impact is denial of service, while privilege escalation would require additional, unproven control over per-CPU memory reuse. The issue appears more consistent with an RCU lifetime/race-condition bug leading primarily to denial of service, as exploitation depends on a narrow teardown race involving a percpu object rather than a generic reclaimable slab object, with no demonstrated privilege-escalation path or obvious controlled overwrite primitive in the relatively niche CAN raw socket subsystem.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.1 | 7.8 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | None | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Alter Execution Logic; Unexpected State
The main problem is that -- if a lock is overcome -- data could be altered in a bad state.
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