PT-2026-29611 · Arm · Mbed Tls

Jaehun Lee · Published 2026-04-01 · Updated 2026-05-05 · CVE-2026-34873

Positive Technologies (AI Summary)

CVSS v3.1

9.1

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Name of the Vulnerable Software and Affected Versions Mbed TLS versions 3.5.0 through 4.0.0

Description A security issue was identified that allows client impersonation during TLS 1.3 session resumption.

Recommendations Update to a version later than 4.0.0.

Fix

Improper Authentication

Weakness Enumeration

CWE-287

Related Identifiers

CVE-2026-34873

OPENSUSE-SU-2026:10498-1

Affected Products

Mbed Tls

References · 20

• https://osv.dev/vulnerability/openSUSE-SU-2026:10498-1 · Vendor Advisory
• https://osv.dev/vulnerability/ROOT-OS-DEBIAN-12-CVE-2026-34873 · Vendor Advisory
• https://mbed-tls.readthedocs.io/en/latest/security-advisories · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-34873 · Vendor Advisory
• https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-client-impersonation-while-resuming-tls13-session · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-34873 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-34873 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-34873 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-34873 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-34873 · Security Note
• https://suse.com/security/cve/CVE-2026-34873 · Note
• https://suse.com/security/cve/CVE-2026-34874 · Note
• https://suse.com/security/cve/CVE-2026-34876 · Note
• https://suse.com/security/cve/CVE-2026-25835 · Note
• https://suse.com/security/cve/CVE-2026-25834 · Note