An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer dereference in distinguished name parsing that allows an attacker to write to address 0.

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:1952-1 advisory.

    This update for ovmf fixes the following issues

    - CVE-2026-25833: mbedtls: buffer underflow in x509_inet_pton_ipv6() (bsc#1261476).
    - CVE-2026-25834: mbedtls: Algorithm downgrade vulnerability (bsc#1261477).
    - CVE-2026-25835: mbedtls: PSA random generator cloning (bsc#1261478).
    - CVE-2026-34874: mbedtls: NULL pointer dereference when setting a distinguished name (bsc#1261469).

    Changes for ovmf:

    - Update mbedtls to 3.6.6.

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.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-3a9536df40 advisory.

    Update to 3.6.6

Tenable has extracted the preceding description block directly from the Fedora 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 Fedora 42 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-10443c65e3 advisory.

    Update to 3.6.6


Tenable has extracted the preceding description block directly from the Fedora 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 Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-8c332fbf00 advisory.

    Update to 3.6.6

Tenable has extracted the preceding description block directly from the Fedora 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 d77bd2f5-34f0-11f1-bc6d-3c7c3fba4204 advisory.

    https://mbed-tls.readthedocs.io/en/latest/security-advisories/ reports:

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.

  - An issue was discovered in Mbed TLS through 3.6.5 and 4.x through 4.0.0. There is a NULL pointer     dereference in distinguished name parsing that allows an attacker to write to address 0. (CVE-2026-34874)

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

ID	Name	Product	Family	Severity
315270	SUSE SLES15 Security Update : ovmf (SUSE-SU-2026:1952-1)	Nessus	SuSE Local Security Checks	high
310670	Fedora 44 : mbedtls (2026-3a9536df40)	Nessus	Fedora Local Security Checks	critical
307409	Fedora 42 : mbedtls (2026-10443c65e3)	Nessus	Fedora Local Security Checks	critical
307056	Fedora 43 : mbedtls (2026-8c332fbf00)	Nessus	Fedora Local Security Checks	critical
305996	FreeBSD : Mbed TLS -- vulnerabilities (d77bd2f5-34f0-11f1-bc6d-3c7c3fba4204)	Nessus	FreeBSD Local Security Checks	critical
304719	Linux Distros Unpatched Vulnerability : CVE-2026-34874	Nessus	Misc.	high

Detections

Analytics

CVE-2026-34874

high

Tenable Plugins

high

critical

critical

critical

critical

high