CVE-2026-98167: Linux kernel · smb: client: fix server->total_read for compound encrypted PDUs
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 28 Oct 2026, 01:27 UTC
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation 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.
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix server->total_read for compound encrypted PDUs In receive_encrypted_standard(), server->total_read is left at the full decrypted frame size when walking sub-PDUs of a compound encrypted frame. As a result, cifs_handle_standard() passes this full size to smb2_check_message(), causing the PDU length guards to incorrectly validate the entire compound frame instead of the current sub-PDU. This allows truncated non-last sub-PDUs to bypass length validation, leading to out-of-bounds reads in smb2_get_data_area_len(). Fix this by setting server->total_read to the true length of the current sub-PDU: next_cmd for non-last sub-PDUs, and the remaining pdu_length for the last one.
References
- ubuntu.com/security/CVE-2026-98167 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98167 (opens in a new tab)
- git.kernel.org/linus/f73726b83e4756fdaa099e1bc1143293bd57ad79 (opens in a new tab)
- git.kernel.org/stable/c/282b72f9a7ef31296c48366db4128882999cc048 (opens in a new tab)
- git.kernel.org/stable/c/8703539d22fdbc13dd2db090ee199c3a427b8ea0 (opens in a new tab)
- git.kernel.org/stable/c/a46eb242e9eef3a3897d166748b23303c516e870 (opens in a new tab)
- git.kernel.org/stable/c/e78fc1d240b27349b45a0f1c3e3c2c401d7e230d (opens in a new tab)
- git.kernel.org/stable/c/ebb8a075fdc7af3d196a4f158a0e18dbc394c0e3 (opens in a new tab)
- git.kernel.org/stable/c/f73726b83e4756fdaa099e1bc1143293bd57ad79 (opens in a new tab)