CVE-2026-80591

Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source

AV:LAttack vector, local

The flaw is reached via local listxattr/flistxattr/listxattrat syscalls through vfs_listxattr into f2fs_listxattr; f2fs is a local block filesystem (Android userdata, embedded flash) and although nfsd/ksmbd can call vfs_listxattr this is a secondary path requiring pre-existing on-disk corruption.

AC:LAttack complexity, low

Once a crafted f2fs image with corrupted xattr entry sizes is mounted, the attacker deterministically controls the on-disk layout that makes list_for_each_xattr iterate past last_base_addr; no race, special memory layout, or rare kernel config is required beyond standard CONFIG_F2FS_FS_XATTR.

PR:LPrivileges required, low

Planting malformed on-disk xattr metadata requires offline image crafting plus CAP_SYS_ADMIN to loop-mount (obtainable in an unprivileged user namespace) or root for raw block writes; triggering listxattr only needs normal file access on the attacker-controlled mount with no capability checks beyond LSM hooks on the syscall path.

UI:NUser interaction, none

In the highest-impact self-contained attack the attacker crafts a malicious f2fs image and mounts it inside their own user namespace, then calls listxattr on their own inode with no victim action such as opening a file or inserting removable media required.

S:UScope, unchanged

The out-of-bounds read corrupts or leaks kernel heap memory within the same kernel security domain; this is a standard local kernel memory-safety flaw, not a VM escape, container breakout, or IOMMU boundary bypass.

C:HConfidentiality impact, high

Before bounds validation f2fs_listxattr reads entry->e_name_index and XATTR_NEXT_ENTRY() fields from xattr entries outside the valid storage area, causing slab out-of-bounds reads of adjacent kernel heap objects that can disclose kernel pointers and sensitive kernel data.

I:HIntegrity impact, high

Although the immediate fault is a read past bounds rather than a write, this is kernel heap memory corruption class behavior; adjacent-slab reads are routinely chained into further kernel exploitation via heap grooming for arbitrary write and code execution, so I:H applies when uncertain.

A:HAvailability impact, high

Reading xattr entry fields beyond the kmalloc-allocated buffer can fault the kernel with a slab out-of-bounds access or oops under KASAN/hardening; f2fs_handle_error may log corruption but does not prevent the out-of-bounds read from destabilizing the system on each listxattr invocation.