What is CVE-2026-34875?

CVE-2026-34875 is a critical-severity vulnerability in Arm Tf-Psa-Crypto, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2026-04-01.

How severe is CVE-2026-34875?

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

Buffer overflow in Arm Tf-Psa-Crypto

CVE-2026-34875

An issue was discovered in Mbed TLS through 3.6.5 and TF-PSA-Crypto 1.0.0. A buffer overflow can occur in public key export for FFDH keys.

Vulnerability class: Buffer Overflow

Published 2026-04-01 · 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: 0.006 (47.5th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

Weakness classification (CWE)

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

References

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

Frequently asked questions

What is CVE-2026-34875?: CVE-2026-34875 is a critical-severity vulnerability in Arm Tf-Psa-Crypto, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2026-04-01.
How severe is CVE-2026-34875?: Critical severity. CVSS v3 base score is 9.8 out of 10.