CVE-2026-98738
Description
A flaw was found in the Linux kernel's Bluetooth subsystem. A race condition occurs when the Security Manager Protocol (SMP) accesses remote Out-of-Band (OOB) pairing data without proper locking while the data is concurrently being removed. A local attacker can exploit this flaw to trigger a use-after-free memory error, resulting in a denial of service (DoS) or potentially arbitrary code execution.
Statement
A race in Bluetooth SMP remote OOB handling allows build_pairing_cmd to retain and read an oob_data entry after a concurrent management command removes and frees it. KASAN confirms a slab use-after-free while the receive path reads the present flag or copies remote random and confirmation values. A Bluetooth peer within radio range can exercise the SMP receive path, but reliable triggering also depends on a concurrent remote OOB removal or update and therefore has high attack complexity. For the CVSS the PR:N value is used for the paranoid adjacent attack scenario because the peer does not need an account or privileges on the target when a legitimate local Bluetooth service performs the concurrent removal. Impact is at least denial of service through a kernel crash and may include confidentiality or integrity impact if reclaimed slab contents are consumed as pairing data.
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 | 5.1 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | None | 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:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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