VulnerabilityPublished 25 Sep 2026Updated 5 Oct 2026

CVE-2026-98020: Linux kernel · pds_core: fix cmd_regs access racing BAR unmap on reset

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-98020· High

Not known to be exploited.

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 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 25 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.

ghsa-qm2m-cwg6-99v6

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 affected Linux kernel versions to properly synchronize access to cmd_regs during BAR unmap and reset operations by taking the devcmd_lock and re-checking cmd_regs in the firmware update download loop. Users should update to the fixed linux-hwe-edge kernel versions listed. No additional mitigation actions are indicated by the vendor advisory.

Description

A vulnerability in the Linux kernel's pds_core component involving race conditions during BAR unmap on reset has been resolved. The issue arises from cmd_regs being accessed concurrently with BAR unmap operations during device reset and firmware update procedures, potentially causing NULL dereferences or writes to unmapped memory. The fix involves proper locking and re-checking of cmd_regs to prevent unsafe access. This vulnerability affects specific linux-hwe-edge kernel versions.

Impact

If exploited, this vulnerability could cause kernel crashes due to NULL pointer dereferences or invalid memory writes, potentially leading to denial of service. The issue arises during concurrent device reset and firmware update operations, affecting system stability. There is no indication of code execution or privilege escalation from the provided data.

Summary

The Linux kernel's pds_core driver had a race condition vulnerability where cmd_regs could be accessed concurrently with BAR unmap operations during reset and firmware update sequences. Specifically, pdsc_reset_prepare() and pdsc_reset_done()'s error path in pdsc_map_bars() cleared and unmapped cmd_regs without holding the devcmd_lock, and pdsc_legacy_firmware_update()'s download loop dereferenced cmd_regs after dropping and reacquiring the lock without re-checking. This could lead to a NULL pointer dereference or writes to unmapped MMIO if a function-level reset (FLR) occurred concurrently with a devlink flash operation. The fix ensures devcmd_lock is held during BAR unmap/remap and cmd_regs is re-checked in the download loop. Additionally, unmap operations are skipped on virtual functions (VFs) since only the physical function (PF) maps cmd_regs and runs devcmd. The reset process and interrupt handling are also properly synchronized to avoid issues. Debugfs readers remain unaffected as they outlive resets and are out of scope for this fix.

GCVE source: db.gcve.eu
OSV ID: UBUNTU-CVE-2026-98020
Osv Schema Version: 1.7.0
Ecosystems: Ubuntu:Pro:14.04:LTS, Ubuntu:Pro:16.04:LTS, Ubuntu:16.04:LTS, Ubuntu:Pro:FIPS:16.04:LTS, Ubuntu:Pro:18.04:LTS, Ubuntu:18.04:LTS, Ubuntu:Pro:FIPS-updates:18.04:LTS, Ubuntu:Pro:FIPS:18.04:LTS, Ubuntu:Pro:20.04:LTS, Ubuntu:20.04:LTS, Ubuntu:Pro:FIPS-updates:20.04:LTS, Ubuntu:Pro:FIPS: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, 17:51 UTC

Technical details

References

Community reviews

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