# AWS-LC X.509 Name Constraints Bypass via Wildcard/Unicode CN

Source: https://junglewise.ai/threats/aws-lc-x-509-name-constraints-bypass-via-wildcard-unicode-cn-3aa77348  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-20  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 4 · Published 2026-03-20

AWS-LC X.509 Name Constraints Bypass via Wildcard/Unicode CN

Technologies: [aws-lc-sys (crates.io)](https://junglewise.ai/threats/technologies/crates-io-aws-lc-sys). Vendors: [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 4, published 20 March 2026.

**Which products and versions are affected?** aws-lc-sys (crates.io) SEMVER:introduced=0.32.0,fixed=0.39.0.

**Is there a fix for This vulnerability?** Yes. aws-lc-sys (crates.io): upgrade to 0.39.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected?** Check whether you run aws-lc-sys (crates.io) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- aws-lc-sys (crates.io): upgrade to 0.39.0 or later

  ```sh
  cargo update -p aws-lc-sys
  ```


## Affected products

- aws-lc-sys (crates.io) SEMVER:introduced=0.32.0,fixed=0.39.0

## Related threats

- [RUSTSEC-2026-0044 - AWS-LC X.509 Name Constraints Bypass via Wildcard/Unicode CN](https://junglewise.ai/threats/rustsec-2026-0044-aws-lc-x-509-name-constraints-bypass-via-wildcard-64993ed0)
- [RUSTSEC-2026-0048 - CRL Distribution Point Scope Check Logic Error in AWS-LC](https://junglewise.ai/threats/cve-2026-4428-aws-aws-lc-revocation-check-bypass-in-x-509-certificate)
- [AWS AWS-LC signature verification bypass in PKCS7_verify](https://junglewise.ai/threats/cve-2026-3338-aws-aws-lc-signature-verification-bypass-in-pkcs7-verify)
- [AWS AWS-LC certificate chain validation bypass in PKCS7_verify](https://junglewise.ai/threats/cve-2026-3336-aws-aws-lc-certificate-chain-validation-bypass-in-pkcs7-verify)
- [RUSTSEC-2026-0043 - Timing Side-Channel in AES-CCM Tag Verification in AWS-LC](https://junglewise.ai/threats/cve-2026-3337-aws-lc-has-timing-side-channel-in-aes-ccm-tag-verification)