PT-2026-61391 · Linux · Linux

CVE-2026-64074 · Published 2026-07-19 · Updated 2026-07-19

NVD

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

In the Linux kernel, the following vulnerability has been resolved:

fs/statmount: fix slab out-of-bounds write in statmount mnt idmap

statmount mnt idmap() writes one mapping with seq printf() and then manually advances seq->count to include the NUL separator.

If seq printf() overflows, seq set overflow() sets seq->count to seq->size. The manual seq->count++ changes this to seq->size + 1. seq has overflowed() then no longer detects the overflow. The corrupted count returns to statmount string(), which later executes:

seq->buf[seq->count++] = '0';

This causes a 1-byte NULL out-of-bounds write on the dynamically allocated seq buffer.

Fix this by checking for overflow immediately after seq printf().

Fix

Related Identifiers

CVE-2026-64074

Affected Products

Linux

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-64074 · Security Note
• https://git.kernel.org/stable/c/93614949dc86f068e3c32c32cf1ee2a2323177a7 · Note
• https://git.kernel.org/stable/c/e37ea2c6f17f273813ea4e8e94c102591d598ce1 · Note
• https://git.kernel.org/stable/c/a3bf0f28d4ba16e1f35f8c983bb04426b87e2a78 · Note