VulnerabilityPublished 17 Sep 2026Updated 5 Oct 2026

CVE-2026-90279: Linux kernel · md/raid5: round bitmap stripes with sector division

Affects Linux kernelSource GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 13:47 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.

microsoft-security-response-ce

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 correct the rounding logic in raid5_bitmap_sector_map(). Users should update to the patched kernel versions listed as affected to resolve this issue. Since this is a kernel-level fix, applying the official kernel updates from the vendor or distribution is the recommended remediation.

Description

A vulnerability in the Linux kernel's md/raid5 component involving incorrect rounding of bitmap stripes with sector division has been resolved. The issue caused misalignment in the mapping of array sectors to component sectors, potentially leading to incorrect RAID5 stripe calculations. This affects specific Linux kernel versions used in various Ubuntu distributions. The severity is assessed as medium based on the described impact.

Impact

The vulnerability could cause incorrect mapping of RAID5 bitmap stripes to component sectors, potentially leading to RAID5 array inconsistencies or data integrity issues during certain write operations. The impact is limited to affected Linux kernel versions running RAID5 configurations with specific chunk and disk setups. There are no known exploits in the wild.

Summary

The vulnerability in the Linux kernel's md/raid5 subsystem relates to the function raid5_bitmap_sector_map(), which rounds bitmap stripes with sector division incorrectly. It aligns the array range to full RAID5 stripe widths before converting to component sectors, but the width calculation (chunk_sectors multiplied by the number of data disks) is not always a power of two. This causes incorrect rounding ranges, demonstrated with a 4-disk RAID5 setup with 1024-sector chunks and three data disks. The old rounding logic produced incorrect component sector ranges, while the fixed implementation uses sector_div() based arithmetic to align the rounded range correctly to the RAID5 stripe width. This fix corrects the deterministic mapper test results and prevents potential RAID5 stripe miscalculations.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Oct 2026, 22:13 UTC

Technical details

References

Community reviews

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