UBUNTU-CVE-2026-12996

Details

ack_write_buf use after free

Affected Packages

openvpn

Ubuntu 20.04 LTS

Affected versions:

2.4.12-0ubuntu0.20.04.12.4.12-0ubuntu0.20.04.22.4.7-1ubuntu22.4.7-1ubuntu2.20.04.22.4.7-1ubuntu2.20.04.32.4.7-1ubuntu2.20.04.4

openvpn

Ubuntu 22.04 LTS

Fixed in:

2.5.11-0ubuntu0.22.04.4

openvpn

Ubuntu 24.04 LTS

Fixed in:

2.6.19-0ubuntu0.24.04.3

openvpn

Ubuntu 25.10

Affected versions:

2.6.13-1ubuntu32.6.14-1ubuntu12.6.14-2ubuntu12.6.14-2ubuntu1.12.6.19-0ubuntu0.25.10.12.6.19-0ubuntu0.25.10.2

openvpn

Ubuntu 26.04 LTS

Fixed in:

2.7.0-1ubuntu1.2

openvpn

Ubuntu Pro 16.04 LTS

Affected versions:

2.3.10-1ubuntu12.3.10-1ubuntu22.3.10-1ubuntu2.12.3.10-1ubuntu2.22.3.10-1ubuntu2.2+esm12.3.10-1ubuntu2.2+esm22.3.7-1ubuntu12.3.7-2ubuntu12.3.8-1ubuntu1

References

REPORT

https://ubuntu.com/security/CVE-2026-12996

ADVISORY

https://ubuntu.com/security/notices/USN-8540-1

REPORT

https://www.cve.org/CVERecord?id=CVE-2026-12996