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AWS-LC has PKCS7_verify Signature Validation Bypass

High severity GitHub Reviewed Published Mar 2, 2026 in aws/aws-lc-rs • Updated Mar 20, 2026

Package

cargo aws-lc-sys (Rust)

Affected versions

>= 0.24.0, < 0.38.0

Patched versions

0.38.0

Description

Summary

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

Impact

Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes.

Customers of AWS services do not need to take action. aws-lc-sys contains code from AWS-LC. Applications using aws-lc-sys should upgrade to the most recent release of aws-lc-sys.

Impacted versions:

aws-lc-sys versions: >= 0.24.0, < 0.38.0

Patches

The patch is included in v0.38.0

Workarounds

There is no workaround. Applications using aws-lc-sys should upgrade to the most recent release of aws-lc-sys.

Resources

If there are any questions or comments about this advisory, contact [AWS/Amazon] Security via the vulnerability reporting page or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.

References

@justsmth justsmth published to aws/aws-lc-rs Mar 2, 2026
Published to the GitHub Advisory Database Mar 3, 2026
Reviewed Mar 3, 2026
Last updated Mar 20, 2026

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

EPSS score

Weaknesses

Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-hfpc-8r3f-gw53

Source code

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