What is CVE-2023-45199?

CVE-2023-45199 is a critical-severity vulnerability in Trustedfirmware Mbed TLS, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2023-10-07.

How severe is CVE-2023-45199?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Trustedfirmware Mbed TLS

CVE-2023-45199

Mbed TLS 3.2.x through 3.4.x before 3.5 has a Buffer Overflow that can lead to remote Code execution.

Vulnerability class: Buffer Overflow

Published 2023-10-07 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (69.3th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.013 · change: +0.002

Affected products

Trustedfirmware Mbed TLS

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory… (Vendor Advisory)

Frequently asked questions

What is CVE-2023-45199?: CVE-2023-45199 is a critical-severity vulnerability in Trustedfirmware Mbed TLS, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2023-10-07.
How severe is CVE-2023-45199?: Critical severity. CVSS v3 base score is 9.8 out of 10.