CVE-2026-80656

A flaw was found in the Linux kernel's hfsplus filesystem. A local attacker could provide a specially crafted and corrupted HFS+ image. When attempting to mount this image, a malformed btree node size value could lead to the use of an uninitialized value within the kernel. This could result in a kernel crash, causing a denial of service (DoS) to the system.

A flaw was found in the Linux kernel's hfsplus filesystem implementation, rated by Red Hat Product Security as Moderate severity. A local attacker able to mount a specially crafted, corrupted HFS+ image could trigger the use of an uninitialized value in the kernel: a malformed btree node size value in the image causes an excessively large record offset to be passed to hfs_bnode_read_u16() during btree node lookup while loading the catalog, which can result in a kernel crash and a denial of service. Exploitation requires local access and the ability to mount an attacker-provided filesystem image, and no impact to confidentiality or integrity has been demonstrated. For these reasons Red Hat assigns this flaw a CVSS 3.1 score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), lower than the upstream CVEORG score of 7.8, which assumes broader privileges and full confidentiality and integrity impact. All currently assessed Red Hat Enterprise Linux kernel and kernel-rt streams and Red Hat In-Vehicle OS kernel streams are marked not affected because the vulnerable code is not present in those shipped kernels; the remaining rhel-6-els stream is out of support scope.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.