CVE-2026-4428: CRL Distribution Point Scope Check Logic Error in AWS-LC

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-19 · updated 2026-06-17
Weakness: CWE-299

Description

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.

Affected products

AWS-LC: from 1.24.0 before 1.71.0 — fixed in 1.71.0
AWS-LC-FIPS: from 3.0.0 before 3.3.0 — fixed in 3.3.0

How to fix

Upgrade to a fixed version: AWS-LC 1.71.0; AWS-LC-FIPS 3.3.0. Check the vendor advisory for mitigations.

References

https://aws.amazon.com/security/security-bulletins/2026-010-AWS/
https://github.com/aws/aws-lc/releases/tag/v1.71.0

Get alerted when CVE-2026-4428 or the next vulnerability affects your stack