CVE-2025-38709: loop: Avoid updating block size under exclusive owner

highCVSS 7CVE-2025-38709

CSIRTS triage

vendor: Linux product: Linux kernel Denial of service

What: Block device loop driver updates block size while owned exclusively, causing potential denial of service.
Who is affected: Linux systems using loop block device driver in affected kernel versions.
Urgency: High urgency; high CVSS score (7.0) indicates significant impact potential despite no active exploitation.
Action: Apply kernel patch as soon as available.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-38709

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2025-387090.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2025-38709	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

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