CVE-2025-70100

Name: CVE-2025-70100
Creator: NVD / NIST
Published: 2026-06-03T14:16:31.217+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.5/10EPSS 0.15%

Last modified Jun 17, 2026

CVE-2025-70100 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. A divide-by-zero vulnerability in the ext4_block_set_lb_size function in src/ext4_blockdev.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by providing a malformed ext4 filesystem image that results in a zero logical block size. The vulnerability is triggered during mount or image processing and leads to a Floating-Point Exception (FPE) under sanitizers or a runtime crash in standard builds due to missing validation of lb_size.. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

Description

A divide-by-zero vulnerability in the ext4_block_set_lb_size function in src/ext4_blockdev.c of the lwext4 1.0.0 library allows attackers to cause a denial of service by providing a malformed ext4 filesystem image that results in a zero logical block size. The vulnerability is triggered during mount or image processing and leads to a Floating-Point Exception (FPE) under sanitizers or a runtime crash in standard builds due to missing validation of lb_size.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS Probability

0.15%

4.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-369

Affected Software

Vendor	Product	Versions
Gkostka	Lwext4	1.0.0

References

https://github.com/gkostka/lwext4/issues/90Exploit, Issue Tracking, Patch
https://github.com/sigdevel/pocs/blob/main/res/lwext4/2/sig8_2_lwext4_ext4_blockdev_c_127Exploit
https://infosec.exchange/@sigdevel/116668952003072580Exploit, Patch, Third Party Advisory
https://github.com/gkostka/lwext4/issues/90Exploit, Issue Tracking, Patch

Timeline

Published: Jun 3, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-70100?

How severe is CVE-2025-70100?

CVE-2025-70100 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.

How do I fix CVE-2025-70100?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-70100?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST