CVE-2026-53320: nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()

mediumCVSS 5.5CVE-2026-53320

CSIRTS triage

vendor: Linux product: nilfs2Other

What: Rejects zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty().
Who is affected: Deployments using nilfs2 filesystem in Linux.
Urgency: Remediation is advised due to the medium severity rating.
Action: Update to the latest kernel version that resolves this issue.

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: medium — CVSS 5.5
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53320

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-2026-533200.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-53320	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

unknownMultiple vulnerabilities in Debian LTS Linux kernel (July 10, 2026)cert-fr-avis
medium[UPDATE] [medium] Linux Kernel: Multiple vulnerabilitiescert-bund
unknownCVE-2026-53320: In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject zero bd_obl…nvd

Recent advisories for nilfs2

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

unknownCVE-2026-53320: In the Linux kernel, the following vulnerability has been resolved: nilfs2: reject zero bd_obl…nvd · 2026-06-26