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CRL Distribution Point Scope Check Logic Error in AWS-LC

High
samuel40791765 published GHSA-q87m-xr7j-vrww Mar 19, 2026

Package

AWS-LC

Affected versions

< v1.71.0

Patched versions

1.71.0
AWS-LC-FIPS
3.0.0
3.3.0

Description

Summary

AWS-LC is an open-source, general-purpose cryptographic library.

Impact

A logic error in CRL distribution point matching in AWS-LC allows a revoked certificate to bypass revocation checks during certificate validation, when the application enables CRL checking and uses partitioned CRLs with Issuing Distribution Point (IDP) extensions.

Customers of AWS services do not need to take action. Applications using AWS-LC should upgrade to the most recent release of AWS-LC.

Impacted versions:

  • AWS-LC >= v1.24.0, < v1.71.0
  • AWS-LC-FIPS >=3.0.0, < 3.3.0

Patches

The patch is included in AWS-LC v1.71.0, AWS-LC-FIPS-3.3.0.

Workarounds

Applications can workaround this issue if they do not enable CRL checking (X509_V_FLAG_CRL_CHECK). Applications using complete (non-partitioned) CRLs without IDP extensions are also not affected.

Otherwise, there is no workaround and applications using AWS-LC should upgrade to the most recent releases of AWS-LC.

References

If you have any questions or comments about this advisory, we ask that you contact AWS Security via our vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVE ID

CVE-2026-4428

Weaknesses

No CWEs