SB20260905101 - Division by zero in Linux kernel ipv6
Published: September 5, 2026
Security Bulletin ID
SB20260905101
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Division by zero (CVE-ID: CVE-2026-80847)
CWE-ID: CWE-369 - Divide By Zero
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 a divide-by-zero error in tcp_select_initial_window() when processing route-derived advertised MSS values. A local user can configure a route with a too-small RTAX_ADVMSS value to cause a denial of service.
The default advertised MSS path is also affected when the effective advertised MSS is reduced by the route MTU and min_adv_mss.
Remediation
Install update from vendor's website.