CVE-2026-55392

EUVD-2026-37927
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
5.5 MEDIUM
LOCAL
LOW
NONE
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: 4%
Debian logo
Debian Releases
Debian Product
Codename
nilfs-tools
bookworm
unimportant
bullseye
unimportant
forky
unimportant
sid
unimportant
trixie
unimportant
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
nilfs-tools
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
ignored
resolute
needs-triage
Common Weakness Enumeration
References
https://github.com/nilfs-dev/nilfs-utils/commit/26efb5daff0757365101035145331b0a5a85d9d9
https://github.com/nilfs-dev/nilfs-utils/issues/26