VulnerabilityPublished 17 Sep 2026Updated 5 Oct 2026

CVE-2026-90284: Linux kernel · firmware_loader: do not queue completed sysfs fallback requests

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 11% 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 address this issue by modifying the firmware loader to avoid queuing already-completed fallback requests. Users should apply the official kernel updates that include this fix. Since this is not a cloud service, remediation requires updating affected Linux kernel versions. Patch status is not explicitly confirmed in the provided data; users should consult the vendor advisory for the latest remediation guidance.

Description

A vulnerability in the Linux kernel firmware loader component could cause a use-after-free condition when handling completed sysfs fallback requests. This occurs because the fallback loading interface is published before the request is fully queued, allowing a userspace helper to complete the request prematurely. The flaw leads to a pointer to freed memory being retained, which can cause faults during subsequent fallback requests. The issue has been resolved by ensuring that completed requests are not re-queued or cause additional events.

Impact

The vulnerability can cause the kernel to retain pointers to freed memory in the firmware loader's fallback request list, potentially leading to faults or crashes during firmware loading fallback operations. This could affect system stability but does not indicate direct privilege escalation or code execution from the provided data.

Summary

The vulnerability in the Linux kernel's firmware_loader involves improper handling of sysfs fallback requests. Specifically, fw_load_sysfs_fallback() calls device_add() before adding the firmware private structure (fw_priv) to the pending_fw_head list. Since device_add() publishes the fallback loading interface, a userspace helper can complete the request before it is queued, leading to firmware_loading_store() calling fw_state_done() while the pending list still points to itself. This results in an unconditional list_add() queuing an already-completed fw_priv. When the request is released, pending_fw_head may retain a pointer to freed memory, causing faults on subsequent fallback requests. The fix returns success immediately if the request is already done after device_add(), preserving the invariant that pending_fw_head only contains active fallback requests.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-90284
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:16.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:22.04:LTS, Ubuntu:Nvidia-BlueField:22.04:LTS, Ubuntu:Pro:FIPS-preview:22.04:LTS, Ubuntu:Pro:FIPS-updates:22.04:LTS, Ubuntu:Pro:Realtime:22.04:LTS, Ubuntu:24.04:LTS, Ubuntu:Nvidia-BlueField:24.04:LTS, Ubuntu:Pro:FIPS-updates:24.04:LTS, Ubuntu:Pro:Realtime:24.04:LTS, Ubuntu:26.04:LTS

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Oct 2026, 22:14 UTC

Technical details

References

Community reviews

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