CVE-2026-34873

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.24% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 15.4% of scored records. A rank, not a probability.

NVD base score

9.1 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Critical. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-04-01 00:00Z5 MO AGO

Last updated

2026-04-02 16:24Z5 MO AGO

Reserved

2026-03-31

Assigning CNA

mitre

Record state

PUBLISHED

Severity

Critical (CVSS 9.1)

CNA CVSS vector

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

Weaknesses

• CWE-287Improper AuthenticationClass
• CWE-290Authentication Bypass by SpoofingBase

Data version

5.2

Document digest

f4f23fc4f299451395f0e804e64da44eb2c3f5a3a6cdde375568cf3da1d7236f

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