CVE-2026-98750
Description
A flaw was found in the Linux kernel's TTY (terminal) subsystem. A race condition occurs when closing a terminal device while the device number is simultaneously re-registered by a driver that does not guarantee minor number exclusivity. A local attacker could exploit this timing window to trigger a use-after-free memory condition, potentially causing a system crash (Denial of Service) or local privilege escalation.
Statement
A race between closing an existing TTY and registering another device with the same minor number can cause saved termios memory to be freed while the close path is still using or updating it. The resulting use after free can cause memory corruption or a kernel crash when device registration overlaps with termios preservation for the old TTY instance. For the CVSS the PR:L value is used because a local user must be able to access and close the affected TTY while device re-registration or minor reuse occurs. AC:H applies because successful triggering depends on a narrow timing window and on a driver that does not guarantee that the reused minor is no longer active. The issue is not directly network reachable. Impact is at least a local denial of service via kernel crash and in the worst case may allow confidentiality or integrity impact and local privilege escalation through reuse of freed kernel memory.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
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