SB20261007163 - Incorrect calculation in Linux kernel mmc host driver



SB20261007163 - Incorrect calculation in Linux kernel mmc host driver

Published: October 7, 2026

Security Bulletin ID SB20261007163
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Incorrect calculation (CVE-ID: CVE-2026-98207)

CWE-ID: CWE-682 - Incorrect Calculation

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause transfer completion accounting to report incorrect byte counts.

The vulnerability exists due to failure to reset the transferred-byte counter in mmc_spi_request() when retrying a multi-block request after a data CRC error. A local user can issue a multi-block transfer request that encounters a CRC error followed by a successful internal retry to cause transfer completion accounting to report incorrect byte counts.

The data itself is retried. Exploitation depends on an MMC-over-SPI system encountering a data CRC error during the transfer.


Remediation

Install update from vendor's website.