SB2026050759 - Integer overflow in Linux kernel net ovpn driver
Published: May 7, 2026
Security Bulletin ID
SB2026050759
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Integer overflow (CVE-ID: CVE-2026-43254)
CWE-ID: CWE-190 - Integer overflow
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an integer overflow in ovpn_tcp_recv when processing coalesced TCP stream data. A remote attacker can send specially crafted TCP stream packets to cause a denial of service.
The issue occurs when large cloned socket buffers contain multiple coalesced packets, which can trigger packet drops during inner packet decapsulation.
Remediation
Install update from vendor's website.