CVE-2026-98126: Linux kernel · smb/client: validate new EOF for zero range
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% 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.
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
This vulnerability has been resolved in the Linux kernel. Users should apply the updated kernel versions that include the fix, which validates the new EOF size before zero-range operations. No additional mitigation steps are required beyond updating to a fixed kernel version.
Description
A vulnerability in the Linux kernel's SMB client implementation allowed file size limits to be bypassed when using the FALLOC_FL_ZERO_RANGE flag without FALLOC_FL_KEEP_SIZE. This could cause the file to grow beyond the caller's file-size limit (RLIMIT_FSIZE). The issue was fixed by validating the new EOF size before sending the zero-range request, preventing unauthorized file growth.
References
- ubuntu.com/security/CVE-2026-98126 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98126 (opens in a new tab)
- git.kernel.org/stable/c/f320ca20c273a26cd779bdb2b2e4b076a95c76f6 (opens in a new tab)
- git.kernel.org/stable/c/06a4f9049cb6dc319bceec2dc813ba89add8b828 (opens in a new tab)
- git.kernel.org/stable/c/88972e35750792e717af287dc71f42a03b5cbce4 (opens in a new tab)
- git.kernel.org/stable/c/3673f057b64abfa957e8ae84448db69369a5091a (opens in a new tab)