VulnerabilityPublished 17 Sep 2026Updated 5 Oct 2026

CVE-2026-90390: Linux kernel · md/bitmap: resume array on backlog_store() error path

Affects Linux kernelSource GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 12:30 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-38.38 23 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1017.17 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1016.16 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1008.9 6 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to address this issue by correctly resuming the array and unlocking the mutex using mddev_unlock_and_resume(). Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, users should consult the vendor or distribution advisory for the latest remediation guidance.

Description

A vulnerability in the Linux kernel's md/bitmap subsystem was resolved. The issue occurs in the backlog_store() function, which suspends the resume array before verifying the presence of a write-mostly device. If no such device exists, the error path fails to properly resume the array, leaving it suspended and blocking subsequent I/O operations. The fix involves using mddev_unlock_and_resume() to correctly release both the suspended state and the mutex lock.

Impact

Affected systems running vulnerable Linux kernel versions may experience blocked I/O operations due to the resume array remaining suspended after an error in backlog_store(). This can degrade system functionality or cause service interruptions related to device-mapper operations involving write-mostly devices.

Summary

CVE-2026-90390 addresses a flaw in the Linux kernel's md/bitmap code where backlog_store() suspends the resume array prematurely on an error path without confirming the existence of a write-mostly device. This leads to the array remaining suspended and blocking further I/O because the error path only unlocks reconfig_mutex without resuming the array. The vulnerability is fixed by employing mddev_unlock_and_resume() to ensure both the suspension and the mutex are properly released, preventing I/O blockage.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Oct 2026, 22:44 UTC

Technical details

References

Community reviews

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