Vulnerability in AWS Aws-Lc

CVE-2026-4428

A logic error in CRL distribution point validation in AWS-LC before 1.71.0 causes partitioned CRLs to be incorrectly rejected as out of scope, which allows a revoked certificate to bypass certificate revocation checks. To remediate this issue, users should upgrade to AWS-LC 1.71.0 or AWS-LC-FIPS-3.3.0.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (17.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-4428: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4428?
CVE-2026-4428 is a high-severity vulnerability in AWS Aws-Lc, classified under Improper Check for Certificate Revocation. CVSS score: 7.4/10. Published 2026-03-19.
How severe is CVE-2026-4428?
High severity. CVSS v3 base score is 7.4 out of 10.