What is CVE-2026-34871?

CVE-2026-34871 is a medium-severity vulnerability in Arm Mbed_tls, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 6.7/10. Published 2026-04-01.

How severe is CVE-2026-34871?

Medium severity. CVSS v3 base score is 6.7 out of 10.

Vulnerability in Arm Mbed_tls

CVE-2026-34871

An issue was discovered in Mbed TLS before 3.6.6 and 4.x before 4.1.0 and TF-PSA-Crypto before 1.1.0. There is a Predictable Seed in a Pseudo-Random Number Generator (PRNG).

EPSS: 0.000 (3.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Arm Mbed_tls
Trustedfirmware Tf-psa-crypto
N/a — versions n/a

Weakness classification (CWE)

CWE-338 — Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

References

cve@mitre.org (Vendor Advisory)
cve@mitre.org (Vendor Advisory)

Frequently asked questions

What is CVE-2026-34871?: CVE-2026-34871 is a medium-severity vulnerability in Arm Mbed_tls, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 6.7/10. Published 2026-04-01.
How severe is CVE-2026-34871?: Medium severity. CVSS v3 base score is 6.7 out of 10.