CVE-2026-90323Hinoki check available

Local teardown hang via premature I/O activation

Published Sep 17, 2026 · Updated Sep 17, 2026

State handling in Linux 6.17 ublk allows local users to hang device teardown via invalid io_uring buffer-registration data. In drivers/block/ublk_drv.c, ublk_fill_io_cmd() marks the I/O tag active before validating sqe->addr, so rejection completes the command while leaving the tag active. Triggering the hang requires access to the local ublk server's device-command path with UBLK_F_AUTO_BUF_REG enabled; the documented consequence is stalled device teardown.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

State handling in Linux 6.17 ublk allows local users to hang device teardown via invalid io_uring buffer-registration data. In drivers/block/ublk_drv.c, ublk_fill_io_cmd() marks the I/O tag active before validating sqe->addr, so rejection completes the command while leaving the tag active. Triggering the hang requires access to the local ublk server's device-command path with UBLK_F_AUTO_BUF_REG enabled; the documented consequence is stalled device teardown.

The record

CVE
CVE-2026-90323
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=52460dda3a775a73f226312b43c0a0211e8665ea <653d22269a8b83b491f7f186a5d7872f14e6ddca
  2. Affected versionversion=52460dda3a775a73f226312b43c0a0211e8665ea <ca5a01eee34c7cbe0f531a613b0292a3ad1a419b
  3. Affected versionversion=6.17

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=52460dda3a775a73f226312b43c0a0211e8665ea <653d22269a8b83b491f7f186a5d7872f14e6ddca; version=52460dda3a775a73f226312b43c0a0211e8665ea <ca5a01eee34c7cbe0f531a613b0292a3ad1a419b; version=6.17

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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