CVE-2026-98173: Linux kernel · smb: client: fix use-after-free of iface in cifs_try_adding_channels()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 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 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 changes the iteration logic to hold references on interface entries during processing and limits retry attempts to prevent infinite loops. Users should apply the official Linux kernel updates that include this patch. Since this is not a cloud service, remediation requires updating affected Linux kernel versions.
Description
A use-after-free vulnerability in the Linux kernel's SMB client implementation was fixed. The flaw occurs in the cifs_try_adding_channels() function when iterating over interface lists without proper reference counting, leading to dereferencing freed memory. This can cause memory corruption with potential impact on confidentiality, integrity, and availability. The issue affects specific Linux kernel versions and has a CVSS score of 7.5 (medium severity).
References
- ubuntu.com/security/CVE-2026-98173 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98173 (opens in a new tab)
- git.kernel.org/linus/d034e836eefd7ce75e588f7031cffbeec594f5ac (opens in a new tab)
- git.kernel.org/stable/c/c941f1ebfd26f683de81091473f3596a218abff0 (opens in a new tab)
- git.kernel.org/stable/c/d034e836eefd7ce75e588f7031cffbeec594f5ac (opens in a new tab)
- git.kernel.org/stable/c/e99040e5e9c60441e6b4725e1a7b88c3106ae903 (opens in a new tab)
- git.kernel.org/stable/c/ec36b38e65596950e6c29bed7dfc90b98707c19c (opens in a new tab)