CVE-2026-53260
Description
A flaw was found in the Linux kernel's TCP request socket path. A race condition can occur on PREEMPT_RT kernels when the reqsk_queue_hash_req function is preempted after setting a timer but before initializing a reference count. If a timer fires during this window while the listener is closing, it can lead to a reference count underflow and a use-after-free condition. This vulnerability could allow a remote attacker to cause a denial of service through a kernel crash or potentially achieve kernel memory corruption, impacting system confidentiality and integrity.
Statement
This vulnerability is rated Moderate impact by Red Hat because triggering the flaw requires an active real-time preemption configuration (PREEMPT_RT) along with precise timing between socket closure and timer expiration. Standard kernel installations are unaffected by default as they run without full real-time preemption enabled. Furthermore, older enterprise platforms including Enterprise Linux 8 and 9 lack the introducing code and are entirely unaffected. Exploitation on susceptible real-time systems could result in kernel memory corruption and denial of service.
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 | 7 | N/A | 9.8 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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