CVE-2026-31449
Description
A flaw was found in the Linux kernel's ext4 filesystem. A local attacker could exploit this vulnerability by providing a specially crafted or corrupted on-disk extent header. This could cause an out-of-bounds read in memory, potentially leading to information disclosure or a system crash (Denial of Service).
Statement
The upstream fix validates p_idx against EXT_LAST_INDEX() before dereferencing extent index entries, returning -EFSCORRUPTED on bad disks. Red Hat considers this primarily relevant to malicious or corrupted ext4 images mounted locally. Errata kernels will carry the patch. Administrators should avoid mounting untrusted ext4 images on sensitive systems until updated.
Mitigation
To mitigate this issue, prevent the ext4 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 | 6.1 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | Low | 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:L/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
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