What is CVE-2018-16870?

CVE-2018-16870 is a medium-severity vulnerability in Wolfssl, classified under Information Disclosure. CVSS score: 5.9/10. Published 2019-01-03.

How severe is CVE-2018-16870?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Information disclosure in Wolfssl

CVE-2018-16870

It was found that wolfssl before 3.15.7 is vulnerable to a new variant of the Bleichenbacher attack to perform downgrade attacks against TLS. This may lead to leakage of sensible data.

Vulnerability class: Information Disclosure

Published 2019-01-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.016 (74.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Wolfssl
Wolfssl — versions before 3.15.7

Weakness classification (CWE)

References

github.com/wolfSSL/wolfssl/pull/1950 (Patch, Third Party Advisory)
cat.eyalro.net/ (Third Party Advisory)

Frequently asked questions

What is CVE-2018-16870?: CVE-2018-16870 is a medium-severity vulnerability in Wolfssl, classified under Information Disclosure. CVSS score: 5.9/10. Published 2019-01-03.
How severe is CVE-2018-16870?: Medium severity. CVSS v3 base score is 5.9 out of 10.