CVE-2026-63893
Description
A flaw was found in the Linux kernel's Thunderbolt property handling. A remote attacker, by acting as a malicious XDomain peer, could craft a special property entry that causes an integer overflow when calculating memory access. This overflow allows the system to read memory outside of the intended buffer, leading to information disclosure through device name or vendor name system attributes. This vulnerability could expose sensitive, untargeted data.
Statement
This vulnerability is rated as Moderate severity for Red Hat products because successful exploitation requires an attacker to physically connect a malicious Thunderbolt device acting as an untrusted XDomain peer. The flaw allows adjacent physical attackers to trigger an out-of-bounds memory read, potentially exposing untargeted kernel memory contents through sysfs device properties rather than granting privilege escalation or arbitrary execution. Additionally, supported Red Hat Enterprise Linux kernels are not affected as they do not include the vulnerable code.
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 | 5.5 | N/A | 8.1 |
| Attack Vector | Local | N/A | Adjacent Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
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