A memory leak in the tls-crypt-v2 client key extraction in OpenVPN 2.5.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote attackers to cause a denial of service (memory exhaustion) via a flood of crafted packets

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3596-1 advisory.

    - CVE-2026-11771: NTLM proxy auth stack off-by-one write (bsc#1273126).
    - CVE-2026-12932: memory leak using --tls-crypt-v2 (bsc#1273127).
    - CVE-2026-12996: Potential DoS and memory leak via TLS session use-after-free (bsc#1273128).
    - CVE-2026-13117: Heap use-after-free via incomplete guard in check_session_buf_not_used() (bsc#1273129).
    - CVE-2026-13379: Windows interactive service DNS SearchList state pollution (bsc#1273130).
    - CVE-2026-35058: improper validation of packet length can lead to a denial of service (bsc#1267945).
    - CVE-2026-40215: race condition during TLS session promotion can lead to a use-after-free (bsc#1267944).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-2038 advisory.

    OpenVPN memory-leak in tls-crypt-v2 client key handling that could lead to out-of-memory situations and     subsequent server crashes (CVE-2026-12932)

    When dynamic tls-crypt is active, it is possible for tls_multi_process to set to_link to     session->tls_wrap_reneg.work and later free that session, leaving to_link.data pointing to freed memory.
    (CVE-2026-13117)

    An internal server error condition that can be triggered by a malicous authenticated client, a very     unlucky corruption of packets in transit or by an attacker that is able to inject a specially created     packet at the right time and is able to observe the traffic to construct the packet. (CVE-2026-13698)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8540-1 advisory.

    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)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - An incomplete guard in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote
    authenticated peers to trigger a use-after-free during TLS session promotion, potentially leading to a
    denial of service or memory leakage (CVE-2026-13117)

  - OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one
    buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response
    from a malicious proxy server (CVE-2026-11771)

  - A memory leak in the tls-crypt-v2 client key extraction in OpenVPN 2.5.0 through 2.6.20 and 2.7_alpha1
    through 2.7.4 allows remote attackers to cause a denial of service (memory exhaustion) via a flood of
    crafted packets (CVE-2026-12932)

  - A use-after-free in OpenVPN 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote authenticated
    peers to potentially cause a denial of service or leak memory via crafted packets during TLS session
    promotion or expiry (CVE-2026-12996)

According to its self-reported version number, the version of OpenVPN installed on the remote Windows host is affected by multiple vulnerabilities:

  - A use-after-free bug in ack_write_buf(), triggerable by a well-timed sequence of control channel and     authentication packets. (CVE-2026-12996)

  - A use-after-free bug in tls_wrap_reneg(), triggerable by a suitable sequence of dynamic tls-crypt     control-channel packets. (CVE-2026-13117)

  - A possible 1-byte buffer overrun on NTLMv2 proxy responses. (CVE-2026-11771)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 12 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-4666 advisory.

    - -----------------------------------------------------------------------     Debian LTS Advisory DLA-4666-1              debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Utkarsh Gupta     July 04, 2026                               https://wiki.debian.org/LTS
    - -----------------------------------------------------------------------

    Package        : openvpn     Version        : 2.6.14-0+deb12u2     CVE ID         : CVE-2026-11771 CVE-2026-12932 CVE-2026-12996 CVE-2026-13117                      CVE-2026-13122 CVE-2026-13698

    Multiple security vulnerabilities were discovered in OpenVPN, which     could result in denial of service.

    For Debian 12 bookworm, these problems have been fixed in version     2.6.14-0+deb12u2.

    We recommend that you upgrade your openvpn packages.

    For the detailed security status of openvpn please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/openvpn

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has a package installed that is affected by multiple vulnerabilities as referenced in the dsa-6376 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6376-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     July 03, 2026                         https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : openvpn     CVE ID         : CVE-2026-11771 CVE-2026-12932 CVE-2026-12996                      CVE-2026-13117 CVE-2026-13122 CVE-2026-13698

    Multiple security vulnerabilities were discovered in OpenVPN, which     could result in denial of service.

    For the stable distribution (trixie), these problems have been fixed in     version 2.6.14-1+deb13u3.

    We recommend that you upgrade your openvpn packages.

    For the detailed security status of openvpn please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/openvpn

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the ffa897a0-756f-11f1-b291-a74de6bb0320 advisory.

    The OpenVPN community project team reports:
    [...] OpenVPN 2.7.5 [...] is a bugfix release fixing several security issues:

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - A memory leak in the tls-crypt-v2 client key extraction in OpenVPN 2.5.0 through 2.6.20 and 2.7_alpha1     through 2.7.4 allows remote attackers to cause a denial of service (memory exhaustion) via a flood of     crafted packets (CVE-2026-12932)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
335070	SUSE SLED15: openvpn / openvpn-auth-pam-plugin / openvpn-dco / openvpn-dco-devel / etc (SUSE-SU-2026:3596-1)	Nessus	SuSE Local Security Checks	Local	high
331992	Amazon Linux 2023 : openvpn, openvpn-devel (ALAS2023-2026-2038)	Nessus	Amazon Linux Local Security Checks	Local	high
326999	Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS : OpenVPN vulnerabilities (USN-8540-1)	Nessus	Ubuntu Local Security Checks	Local	high
444654	Alpine: multiple openvpn packages: security update to 2.7.5-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	high
444654	Alpine: multiple openvpn packages: security update to 2.7.5-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	high
325894	OpenVPN 2.6.0 < 2.6.21 / 2.7.x < 2.7.5 Multiple Vulnerabilities	Nessus	Windows	Local	high
325054	Debian dla-4666 : openvpn - security update	Nessus	Debian Local Security Checks	Local	high
325052	Debian dsa-6376 : openvpn - security update	Nessus	Debian Local Security Checks	Local	high
324994	FreeBSD : openvpn -- multiple vulnerabilities (ffa897a0-756f-11f1-b291-a74de6bb0320)	Nessus	FreeBSD Local Security Checks	Local	high
324982	Linux Distros Unpatched Vulnerability : CVE-2026-12932	Nessus	Misc.	Local	high

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CVE-2026-12932

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