SB20260727365 - Out-of-bounds write in Linux kernel netfs
Published: July 27, 2026
Security Bulletin ID
SB20260727365
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Out-of-bounds write (CVE-ID: CVE-2026-64217)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to an out-of-bounds write in netfs_extract_user_iter() when extracting user-supplied pages from an iov_iter. A local user can trigger an extract_pages overrun to cause memory corruption.
The issue occurs if iov_iter_extract_pages() overfills the pages array, causing excess pages to be included in the constructed iterator.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/00efe58bbdcc93272d579ca24bfc912563f4a204
- https://git.kernel.org/stable/c/0ef37eef83fad3542ee06db2940433ae1a92b39d
- https://git.kernel.org/stable/c/96cc3beb2390ba9f9c128c5733c0ccfe450dd4f9
- https://git.kernel.org/stable/c/afeb32d9bf9aaeea51d0f723a19f14afb73bd94d
- https://git.kernel.org/stable/c/f48b9157f0f611fa436c360648603d5ded719b12