Vulnerability in Amazon Aws-Lc-Sys

CVE-2026-3336

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 AWS-LC version 1.69.0.

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (32.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 32.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3336: held from 0.008 to 0.004.

EPSS over last 30 days · oldest: 0.008 · newest: 0.004 · change: -0.004

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3336?
CVE-2026-3336 is a high-severity vulnerability in Amazon Aws-Lc-Sys, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2026-03-02.
How severe is CVE-2026-3336?
High severity. CVSS v3 base score is 7.5 out of 10.