CVE-2025-70100Public exploit

Application crash via unchecked zero logical block size

Published Jun 3, 2026 · Updated Jun 3, 2026

Divide-by-zero in lwext4 1.0.0 allows attackers to crash applications by supplying a malformed ext4 filesystem image. During ext4_mount, ext4_block_set_lb_size in src/ext4_blockdev.c uses a zero lb_size in arithmetic without validating it. Processing or mounting the attacker-supplied image is required, and the resulting division by zero terminates the consuming process.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Divide-by-zero in lwext4 1.0.0 allows attackers to crash applications by supplying a malformed ext4 filesystem image. During ext4_mount, ext4_block_set_lb_size in src/ext4_blockdev.c uses a zero lb_size in arithmetic without validating it. Processing or mounting the attacker-supplied image is required, and the resulting division by zero terminates the consuming process.

The record

CVE
CVE-2025-70100
Published
Jun 3, 2026
Updated
Jun 3, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-369, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-369Divide By Zero
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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