VulnerabilityPublished 18 Oct 2026

CVE-2026-98821: Linux kernel · block: reject polled dio with user integrity metadata

Source GCVE Database

Authoritative record:CVE-2026-98821· High

Not known to be exploited · fixed in dd33c03cefccdfcb223e9e6262643d64f8c1ae20 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in dd33c03cefccdfcb223e9e6262643d64f8c1ae20, c97ef13ad96be0e08af38dfa2ed40cded0b53e1b, 6.17 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 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.

ghsa-4mqf-mrhr-h3rh

What to do

Upgrade Linux kernel to dd33c03cefccdfcb223e9e6262643d64f8c1ae20, c97ef13ad96be0e08af38dfa2ed40cded0b53e1b, 6.17 or 2a42e6fe1293f2e2d579c9fe5bbab056dd8b880e.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=6.16.8 <6.17	Fixed in dd33c03cefccdfcb223e9e6262643d64f8c1ae20 c97ef13ad96be0e08af38dfa2ed40cded0b53e1b 6.17 2a42e6fe1293f2e2d579c9fe5bbab056dd8b880e
LinuxLinux	Affected =6.17	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to reject polled direct I/O operations with user integrity metadata. Systems should apply the official kernel update that includes this fix. Until patched, avoid using polled DIO with user metadata and HIPRI combinations on integrity devices. Patch status is not explicitly stated in the input data; check the vendor advisory for the current remediation guidance.

Description

A vulnerability in the Linux kernel related to block device polled direct I/O (DIO) with user integrity metadata has been resolved. The issue arises because IOCB_HAS_METADATA leaves iocb->private as a uio_meta, but iocb_bio_iopoll() expects a bio, causing a mismatch. This leads to a general protection fault and kernel crash when io_uring IOPOLL is used with a PI attribute on an integrity device. The fix involves rejecting polled DIO with user metadata and returning -EOPNOTSUPP when HIPRI is combined with user metadata.

References

Community reviews

Loading reviews…