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PKCS7_verify Certificate Chain Validation Bypass in AWS-LC

High
torben-hansen published GHSA-cfwj-9wp5-wqvp Mar 2, 2026

Package

AWS-LC

Affected versions

>= v1.41, < v1.69.0

Patched versions

v1.69.0

Description

Summary

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

Impact

Improper certificate validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass certificate chain verification when processing PKCS7 objects with multiple signers, except the final signer.

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

From v1.41.0 through v1.68.0.

Patches

The patch is included in v1.69.0.

Workarounds

There is no workaround. Applications using AWS-LC should upgrade to the most recent release 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.

Acknowledgement

We would like to thank Joshua Rogers (https://joshua.hu/) of AISLE Research Team (https://aisle.com) for collaborating on this issue through the coordinated vulnerability disclosure process.

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
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
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:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CVE ID

CVE-2026-3336

Weaknesses

No CWEs