CVE-2026-23338: Linux kernel · drm/amdgpu/userq: Do not allow userspace to trivially triger kernel warnings
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Mar 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 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/userq: Do not allow userspace to trivially triger kernel warnings Userspace can either deliberately pass in the too small num_fences, or the required number can legitimately grow between the two calls to the userq wait ioctl. In both cases we do not want the emit the kernel warning backtrace since nothing is wrong with the kernel and userspace will simply get an errno reported back. So lets simply drop the WARN_ONs. (cherry picked from commit 2c333ea579de6cc20ea7bc50e9595ef72863e65c)
References
- ubuntu.com/security/CVE-2026-23338 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23338 (opens in a new tab)
- git.kernel.org/linus/7b7d7693a55d606d700beb9549c9f7f0e5d9c24f (opens in a new tab)
- git.kernel.org/stable/c/1753f5f81ab60a553287f9ee659a6ac363adf8d7 (opens in a new tab)
- git.kernel.org/stable/c/7321302edca3a349ddaea689df95b986beee6c4a (opens in a new tab)
- git.kernel.org/stable/c/7b7d7693a55d606d700beb9549c9f7f0e5d9c24f (opens in a new tab)