nilfs-dev nilfs-utils up to 2.3.0 nilfs_sb_is_valid improper validation of specified quantity in input

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4.3	$0-$5k	1.94+

Summaryinfo

A vulnerability, which was classified as problematic, was found in nilfs-dev nilfs-utils up to 2.3.0. Affected by this vulnerability is the function nilfs_sb_is_valid. Executing a manipulation can lead to improper validation of specified quantity in input. This vulnerability is tracked as CVE-2026-55392. The attack is restricted to local execution. No exploit exists. It is best practice to apply a patch to resolve this issue.

Detailsinfo

A vulnerability has been found in nilfs-dev nilfs-utils up to 2.3.0 and classified as problematic. This vulnerability affects the function nilfs_sb_is_valid. The manipulation with an unknown input leads to a improper validation of specified quantity in input vulnerability. The CWE definition for the vulnerability is CWE-1284. The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties. As an impact it is known to affect availability. CVE summarizes:

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 weakness was disclosed by Tristan Madani as 26. The advisory is available at github.com. This vulnerability was named CVE-2026-55392 since 06/16/2026. The exploitation appears to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

Applying the patch 26efb5daff0757365101035145331b0a5a85d9d9 is able to eliminate this problem. The bugfix is ready for download at github.com.

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Productinfo

Vendor

nilfs-dev

Name

nilfs-utils

Version

License

open-source

Website

Product: https://github.com/nilfs-dev/nilfs-utils/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper validation of specified quantity in input
CWE: CWE-1284 / CWE-703
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 26efb5daff0757365101035145331b0a5a85d9d9

Timelineinfo

06/16/2026 CVE reserved
06/19/2026 +3 days Advisory disclosed
06/19/2026 +0 days VulDB entry created
06/19/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 26
Researcher: Tristan Madani
Status: Confirmed

CVE: CVE-2026-55392 (🔒)
GCVE (CVE): GCVE-0-2026-55392
GCVE (VulDB): GCVE-100-372262

Entryinfo

Created: 06/19/2026 07:39
Changes: 06/19/2026 07:39 (78)
Complete: 🔍
Cache ID: 216::103