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CVE-2026-98167

Linux: smb: client: fix server->total_read for compound encrypted PDUs

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.22%Chance of exploitation activity in the next 30 days, higher than 11% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in8703539d22fdbc13dd2db090ee199c3a427b8ea0Also 282b72f9a7ef31296c48366db4128882999cc048CVE List
Published6 Oct 2026Updated 19 Oct 2026CVE List

What fixes it

  • 8703539d22fdbc13dd2db090ee199c3a427b8ea0LinuxCVE List
  • 282b72f9a7ef31296c48366db4128882999cc048LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 14

  • Linuxaffected: b24df3e30cbf48255db866720fb71f14bf9d2f39 before 8703539d22fdbc13dd2db090ee199c3a427b8ea0CVE List
  • Linuxaffected: b24df3e30cbf48255db866720fb71f14bf9d2f39 before e78fc1d240b27349b45a0f1c3e3c2c401d7e230dCVE List
  • Linuxaffected: b24df3e30cbf48255db866720fb71f14bf9d2f39 before a46eb242e9eef3a3897d166748b23303c516e870CVE List
  • Linuxaffected: b24df3e30cbf48255db866720fb71f14bf9d2f39 before ebb8a075fdc7af3d196a4f158a0e18dbc394c0e3CVE List
  • Linuxaffected: b24df3e30cbf48255db866720fb71f14bf9d2f39 before 282b72f9a7ef31296c48366db4128882999cc048CVE List
  • Linuxaffected: b24df3e30cbf48255db866720fb71f14bf9d2f39 before f73726b83e4756fdaa099e1bc1143293bd57ad79CVE List
  • Linuxaffected: 4.19CVE List
  • Linuxunaffected: all versions before 4.19CVE List
  • Linuxunaffected: 6.1.189 through 6.1.*CVE List
  • Linuxunaffected: 6.6.158 through 6.6.*CVE List
  • Linuxunaffected: 6.12.112 through 6.12.*CVE List
  • Linuxunaffected: 6.18.54 through 6.18.*CVE List
  • Linuxunaffected: 7.2.8 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 6