Paper/Archive/CVE-2026-34873

CVE-2026-34873

mitre — An issue was discovered in Mbed TLS 3.5.0 through 4.0.0.

EPSS 0.3%CVSS 9.1

critical.is priorityof 100

31

CVSS 9.1 (ADP)9.1 / 10 × 3027.3 Not in CISA KEV+300.0 EPSS percentile 16.5.165 × 203.3 No public exploit+100.0 SSVC exploitation: none+100.0

Description · from the CVE record

An issue was discovered in Mbed TLS 3.5.0 through 4.0.0. Client impersonation can occur while resuming a TLS 1.3 session.

Affected

ProductAffectedFixed inSource

n/an/a–CNA

Scores by source

CISA ADP9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refmbed-tls.readthedocs.io/en/latest/security-advisories refmbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-client-impersonation-while-resuming-tls13-session