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CVE intelligence

CVE-2025-38709

Vulnerability intelligence

Published Sep 4, 2025Sources checked Sep 30, 2026
5.5MEDIUMCVSS out of 10
What this means

Review the available evidence

CVE-2025-38709 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

CISA KEVNot listedBased on the latest collected catalog
EPSS0.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview

What is CVE-2025-38709?

In the Linux kernel, the following vulnerability has been resolved: loop: Avoid updating block size under exclusive owner Syzbot came up with a reproducer where a loop device block size is changed underneath a mounted filesystem. This causes a mismatch between the block device block size and the block size stored in the superblock causing confusion in various places such as fs/buffer.c. The particular issue triggered by syzbot was a warning in __getblk_slow() due to requested buffer size not matching block device block size. Fix the problem by getting exclusive hold of the loop device to change its block size. This fails if somebody (such as filesystem) has already an exclusive ownership of the block device and thus prevents modifying the loop device under some exclusive owner which doesn't expect it.