========================================================================== Ubuntu Security Notice USN-8540-1 July 14, 2026
openvpn vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 26.04 LTS - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS Summary: Several security issues were fixed in OpenVPN. Software Description: - openvpn: virtual private network software Details: It was discovered that OpenVPN had a 1-byte buffer overrun when handling NTLMv2 proxy responses. An attacker could use this issue to cause a denial of service or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-11771) It was discovered that OpenVPN incorrectly handled metadata when extracting tls-crypt-v2 client keys. An attacker could possibly use this issue to obtain sensitive information. (CVE-2026-12932) It was discovered that OpenVPN had a use-after-free in the ack_write_buf handling. An attacker could use this issue to cause OpenVPN to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-12996) It was discovered that OpenVPN had a use-after-free in the tls_wrap_reneg handling. An attacker could use this issue to cause OpenVPN to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-13117) It was discovered that OpenVPN incorrectly validated authentication tokens when external authentication was enabled. A remote attacker could possibly use this issue to cause OpenVPN to crash, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-13122) It was discovered that OpenVPN had a memory leak when handling tls-crypt-v2 client keys. A remote attacker with a valid tls-crypt-v2 client key could possibly use this issue to cause OpenVPN to consume excessive resources, leading to a denial of service. (CVE-2026-13698) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 26.04 LTS openvpn 2.7.0-1ubuntu1.2 Ubuntu 24.04 LTS openvpn 2.6.19-0ubuntu0.24.04.3 Ubuntu 22.04 LTS openvpn 2.5.11-0ubuntu0.22.04.4 After a standard system update you need to restart OpenVPN to make all the necessary changes. References: https://ubuntu.com/security/notices/USN-8540-1 CVE-2026-11771, CVE-2026-12932, CVE-2026-12996, CVE-2026-13117, CVE-2026-13122, CVE-2026-13698 Package Information: https://launchpad.net/ubuntu/+source/openvpn/2.7.0-1ubuntu1.2 https://launchpad.net/ubuntu/+source/openvpn/2.6.19-0ubuntu0.24.04.3 https://launchpad.net/ubuntu/+source/openvpn/2.5.11-0ubuntu0.22.04.4
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Description: OpenPGP digital signature
