CVE-2026-68450
Description
A flaw was found in the Linux kernel's btrfs filesystem. When the __add_reloc_root() function attempts to insert a duplicate mapping node into the reloc_root_tree, the newly allocated node is not properly freed. This oversight can lead to a memory leak, potentially causing resource exhaustion and a Denial of Service (DoS) over an extended period if this unexpected path is triggered.
Statement
Red Hat has determined that this vulnerability does not pose a significant risk. The memory leak occurs on a defensive error path that upstream callers assert should never be reached, and triggering btrfs relocation requires administrative privileges. Red Hat may apply this fix in a future kernel update.
Mitigation
There is no mitigation for this flaw. Systems not using btrfs filesystems are not affected in practice, as the vulnerable code path is only reached during btrfs block group relocation operations.
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 | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | 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:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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