CVE-2026-98405: Linux kernel · smb: client: fix missing iov bounds check in parse_posix_sids()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High.
Data as of 27 Oct 2026, 09:02 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 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 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-aws-6.17pkg:deb/ubuntu/linux-aws-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.14pkg:deb/ubuntu/linux-azure-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.17pkg:deb/ubuntu/linux-azure-6.17?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-fde-6.14pkg:deb/ubuntu/linux-azure-fde-6.14?arch=source&distro=nobleOther 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 rejects malformed SMB responses with invalid length fields causing out-of-bounds reads. Users should apply the updated Linux kernel versions that include this patch. No additional mitigations are indicated by the vendor advisory.
Description
A high-severity vulnerability in the Linux kernel SMB client was fixed by adding proper bounds checking in the parse_posix_sids() function. The flaw allowed out-of-bounds reads of kernel memory due to improper validation of server-supplied length values. This could lead to information disclosure and denial of service.
References
- ubuntu.com/security/CVE-2026-98405 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98405 (opens in a new tab)
- git.kernel.org/stable/c/d91b9a3b2b38e5ac1b51e9e5b23fe53ad7b49644 (opens in a new tab)
- git.kernel.org/stable/c/2f8ed71aaaba3bc8b19cd9930cc62e63e142b299 (opens in a new tab)
- git.kernel.org/stable/c/b09d092eb24ad0110f16a9b7c1ed5d2a0c1733dc (opens in a new tab)
- git.kernel.org/stable/c/eac6917a42899aad0617bbf04798c5dd946a1fe5 (opens in a new tab)
- git.kernel.org/stable/c/b862996e5105be1293da9cdc85da77b76021c3bd (opens in a new tab)