SB2026090591 - Out-of-bounds write in Linux kernel tls



SB2026090591 - Out-of-bounds write in Linux kernel tls

Published: September 5, 2026

Security Bulletin ID SB2026090591
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds write (CVE-ID: CVE-2026-80852)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an out-of-bounds write in tls_append_frag() in the TLS device offload implementation when repeatedly splicing small amounts of data into a TLS_TX_ZEROCOPY_RO socket using SPLICE_F_MORE and MSG_MORE. A local user can cause the fragment count to exceed the maximum array bound to cause a denial of service.

The vulnerable path requires TLS device offload support.


Remediation

Install update from vendor's website.