CVE-2026-55392CWE-1284

NILFS utilities - Undefined Behavior and Out-of-Memory via Unvalidated s_log_block_size

Medium · published June 18, 2026

CVSS v4.0
6.7
EPSS
0%
Percentile
3.9
In the wild
Unconfirmed
What it is

NILFS utilities through 2.3.0, fixed in commit 26efb5d, nilfs_sb_is_valid() function fails to validate s_log_block_size field in NILFS2 superblock before bit-shift operations. Attackers supplying crafted NILFS2 images trigger undefined behavior through oversized shifts or out-of-memory conditions, crashing tools like nilfs-tune and dumpseg.

The record
Technical detail
CVSS v4.0
6.7 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00151 · 3.9th percentile
Weakness
CWE-1284 · Improper Validation of Specified Quantity in Input
Published
2026-06-18T18:00Z
EPSS history
Timeline
  • 18 JUN 18:00Z
    NILFS utilities - Undefined Behavior and Out-of-Memory via Unvalidated s_log_block_size
    cvelistv5