How to Fix CVE-2026-3338: AWS-LC (Bundle Sibling)
By Sai Kiran Pandrala. Last verified: 2026-05-25.
CVE-2026-3338 is a sibling vulnerability in the same vendor advisory as CVE-2026-3336. Apply the same patched build and you close both. The technical detail below is what differs.
| Severity | 7.5 (High) |
|---|---|
| Actively exploited? | No public listing in CISA KEV |
| Affected | AWS-LC 1.41.0 to <1.69.0 |
| Fixed in | Same patched build as CVE-2026-3336 |
| Type (CWE) | CWE-347 (Improper Verification of Cryptographic Signature) |
What's different about CVE-2026-3338?
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.
How to fix CVE-2026-3338
Apply the patched build per the primary write-up: How to Fix CVE-2026-3336. All commands, verification steps, and rollback notes for AWS-LC are listed there.
Frequently asked questions
Does the CVE-2026-3336 patch close CVE-2026-3338?
Yes. Both CVEs are addressed by the same vendor patch. Applying the patched build closes the full bundle.
Is CVE-2026-3338 listed in CISA KEV?
No public KEV listing at the time of this writing.
Where is the official advisory?
See https://aws.amazon.com/security/security-bulletins/2026-005-AWS/
References
- Official vendor advisory: https://aws.amazon.com/security/security-bulletins/2026-005-AWS/
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3338
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary: How to Fix CVE-2026-3336
*Written by Sai Kiran Pandrala. Part of the AWS-LC bundle. Full procedure at how-to-fix-cve-2026-3336.*