CVE-2026-3338
PKCS7_verify Signature Validation Bypass in AWS-LC
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.
INFO
Published Date :
March 2, 2026, 10:16 p.m.
Last Modified :
March 11, 2026, 4:54 p.m.
Remotely Exploit :
Yes !
Source :
ff89ba41-3aa1-4d27-914a-91399e9639e5
Affected Products
The following products are affected by CVE-2026-3338
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 | ||||
| CVSS 4.0 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 |
Solution
- Upgrade AWS-LC to version 1.69.0.
- Verify signature validation in applications.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-3338.
| URL | Resource |
|---|---|
| https://aws.amazon.com/security/security-bulletins/2026-005-AWS/ | Vendor Advisory |
| https://github.com/aws/aws-lc/releases/tag/v1.69.0 | Release Notes |
| https://github.com/aws/aws-lc/security/advisories/GHSA-jchq-39cv-q4wj | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-3338 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-3338
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-3338 vulnerability anywhere in the article.
-
CybersecurityNews
Amazon AWS-LC Vulnerabilities Allows Attackers to Bypass Certificate Chain Verification
Amazon AWS-LC Vulnerabilities Bypass Certificate Chain Verification A critical security bulletin addressing three distinct vulnerabilities in AWS-LC, its open-source, general-purpose cryptographic lib ... Read more
-
Daily CyberSecurity
Cracking the Cloud’s Crypto: Unauthenticated Bypass Flaws Found in Amazon’s AWS-LC Library
Cybersecurity researchers have identified three significant vulnerabilities in AWS-LC, Amazon’s open-source cryptographic library used extensively across its cloud infrastructure and global services. ... Read more
The following table lists the changes that have been made to the
CVE-2026-3338 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Reanalysis by [email protected]
Mar. 11, 2026
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:aws:aws_libcrypto:*:*:*:*:*:*:*:* versions from (including) 1.41.0 up to (excluding) 1.69.0 OR *cpe:2.3:a:amazon:aws_libcrypto:*:*:*:*:*:*:*:* versions from (including) 1.41.0 up to (excluding) 1.69.0 *cpe:2.3:a:amazon:aws-lc-sys:*:*:*:*:*:rust:*:* versions from (including) 0.24.0 up to (excluding) 0.38.0 -
Initial Analysis by [email protected]
Mar. 11, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:aws:aws_libcrypto:*:*:*:*:*:*:*:* versions from (including) 1.41.0 up to (excluding) 1.69.0 Added Reference Type AMZN: https://aws.amazon.com/security/security-bulletins/2026-005-AWS/ Types: Vendor Advisory Added Reference Type AMZN: https://github.com/aws/aws-lc/releases/tag/v1.69.0 Types: Release Notes Added Reference Type AMZN: https://github.com/aws/aws-lc/security/advisories/GHSA-jchq-39cv-q4wj Types: Vendor Advisory -
CVE Modified by ff89ba41-3aa1-4d27-914a-91399e9639e5
Mar. 02, 2026
Action Type Old Value New Value Added Reference https://github.com/aws/aws-lc/security/advisories/GHSA-jchq-39cv-q4wj -
New CVE Received by ff89ba41-3aa1-4d27-914a-91399e9639e5
Mar. 02, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-347 Added Reference https://aws.amazon.com/security/security-bulletins/2026-005-AWS/ Added Reference https://github.com/aws/aws-lc/releases/tag/v1.69.0