CVE-2026-90023: Linux kernel · usb: gadget: f_mass_storage: fix null pointer dereference in
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 16 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.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| 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 is available that adds proper validation for the number of buffers in the f_mass_storage driver. Users should apply the official Linux kernel patches that address CVE-2026-90023. Check your Linux distribution's security advisories for updated kernel versions containing this fix and upgrade accordingly.
Description
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_mass_storage: fix null pointer dereference in fsg_common_set_num_buffers() Previously fsg_num_buffers_validate() was removed as it was not necessary due to Kconfig setting the limits for n from 2 to 256 with default as 2. However, setting the page content in such a way that kstrtou8() reflects n value as either 0 or 1 bypasses these restrictions leading to a null pointer dereference if n is 0. Fix this by adding a check for n < 2 and returning -EINVAL if n is either 0 or 1 consistent with Kconfig logic.
References
- ubuntu.com/security/CVE-2026-90023 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90023 (opens in a new tab)
- git.kernel.org/linus/2c0f5ca48674a5b5f9fa4a9c3325aa48053af0bc (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-90023 (opens in a new tab)
- git.kernel.org/stable/c/2c0f5ca48674a5b5f9fa4a9c3325aa48053af0bc (opens in a new tab)
- git.kernel.org/stable/c/51cc9af4f2d3f0b765266aced66b9b532b423b13 (opens in a new tab)
- git.kernel.org/stable/c/9e8dd2a7a8ccbb756771ad985b0ad3387ed3c957 (opens in a new tab)
- git.kernel.org/stable/c/b9b5b5df5b8dd3c1572ed267200276a44cc67d8e (opens in a new tab)