CVE-2026-64378: writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()

mediumCVSS 4.7CVE-2026-64378

CSIRTS triage

vendor: Linux product: kernelOther

What: A race condition exists between cgroup_writeback_umount() and inode_switch_wbs() functions.
Who is affected: Deployments of the Linux kernel utilizing cgroups may be affected.
Urgency: Remediation is important to prevent potential data corruption, though exploitation is not currently known.
Action: Monitor for updates regarding 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 4.7
Published: 2026-07-14
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64378

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-2026-643780.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-64378	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

highCVE-2026-64378: In the Linux kernel, the following vulnerability has been resolved: writeback: fix race betwee…nvd

Recent advisories for writeback

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.

highCVE-2026-64378: In the Linux kernel, the following vulnerability has been resolved: writeback: fix race betwee…nvd · 2026-07-25
highCVE-2026-64058: In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_read_foli…nvd · 2026-07-19
highCVE-2026-63951: In the Linux kernel, the following vulnerability has been resolved: zram: fix use-after-free i…nvd · 2026-07-19
unknownCVE-2026-53393: In the Linux kernel, the following vulnerability has been resolved: nfsd: reset write verifier…nvd · 2026-07-19
mediumCVE-2026-53393: nfsd: reset write verifier on deferred writeback errorsmsrc · 2026-07-14
mediumCVE-2026-52960: ceph: put folios not suitable for writebackmsrc · 2026-06-09