SB20260912215 - Double free in Linux kernel ipv6
Published: September 12, 2026
Security Bulletin ID
SB20260912215
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) Double free (CVE-ID: CVE-2026-89563)
CWE-ID: CWE-415 - Double Free
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 double free in ip6_tnl_xmit() when handling errors after expanding packet headroom. A local user can trigger an error after packet headroom expansion to cause a denial of service.
The issue is reachable when collect_md tunnels reject a non-NONE encapsulation type or when ip6_tnl_encap() fails.
Remediation
Install update from vendor's website.