CVE-2026-31666
Description
A flaw was found in the Linux kernel's btrfs filesystem. An incorrect return value in the lookup_extent_data_ref() function can lead to the system believing a lookup succeeded when it did not. This can cause operations to be performed on the wrong extent tree item, potentially resulting in data corruption within the extent tree.
Statement
Btrfs extent-data-ref lookup could return wrong success after a leaf split; upstream returns the correct error. Red Hat recommends btrfs users install corrected kernels to avoid metadata mis-decisions.
Mitigation
To mitigate this issue, prevent the btrfs module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.
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 | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | High |
| 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Unexpected State; Alter Execution Logic
This weakness could place the system in a state that could lead unexpected logic to be executed or other unintended behaviors.
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