CVE-2026-3336: CWE-295 (Improper Certificate Validation) in AWS AWS-LC
Bulletin ID: 2026-005-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 2026/03/02 14:30 PM PST Description: AWS-LC is an open-source, general-purpose cryptographic library. We identified three distinct issues: - CVE-2026-3336: PKCS7_verify Certificate Chain Validation Bypass in AWS-LC 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. - CVE-2026-3337: Timing Side-Channel in AES-CCM Tag Verification in AWS-LC Observable timing discrepancy in AES-CCM decryption in AWS-LC allows an unauthenticated user to potentially determine authentication tag validity via timing analysis. - CVE-2026-3338: PKCS7_verify Signature Validation bypass in AWS-LC Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes. Impacted versions: - PKCS7_verify Certificate Chain Validation Bypass in AWS-LC >= v1.41.0, = v0.24.0, = v1.21.0, = AWS-LC-FIPS-3.0.0, = v0.14.0, = v0.13.0, = v1.41.0, = v0.24.0, < v0.38.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-3336) involves improper certificate validation (CWE-295) in the PKCS7_verify() function of AWS-LC. Specifically, when processing PKCS7 objects containing multiple signers, the certificate chain verification can be bypassed for all but the final signer. This flaw could allow an unauthenticated user to circumvent intended certificate validation checks. AWS manages remediation for its cloud services, and users of AWS-LC are advised to upgrade to version 1.69.0 where the issue is fixed.
Potential Impact
The vulnerability allows an unauthenticated attacker to bypass certificate chain verification for multiple signers in PKCS7 objects, potentially undermining the integrity of signature validation processes. This could lead to acceptance of forged or invalid signatures except for the final signer, impacting the trustworthiness of cryptographic operations relying on AWS-LC. There is no indication of confidentiality or availability impact. No known exploits in the wild have been reported.
Mitigation Recommendations
AWS manages remediation for this vulnerability in its cloud services, so customers using AWS services do not need to take action. Applications that directly use AWS-LC should upgrade to AWS-LC version 1.69.0, which contains the official fix for this issue.
CVE-2026-3336: CWE-295 (Improper Certificate Validation) in AWS AWS-LC
Description
Bulletin ID: 2026-005-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 2026/03/02 14:30 PM PST Description: AWS-LC is an open-source, general-purpose cryptographic library. We identified three distinct issues: - CVE-2026-3336: PKCS7_verify Certificate Chain Validation Bypass in AWS-LC 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. - CVE-2026-3337: Timing Side-Channel in AES-CCM Tag Verification in AWS-LC Observable timing discrepancy in AES-CCM decryption in AWS-LC allows an unauthenticated user to potentially determine authentication tag validity via timing analysis. - CVE-2026-3338: PKCS7_verify Signature Validation bypass in AWS-LC Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes. Impacted versions: - PKCS7_verify Certificate Chain Validation Bypass in AWS-LC >= v1.41.0, = v0.24.0, = v1.21.0, = AWS-LC-FIPS-3.0.0, = v0.14.0, = v0.13.0, = v1.41.0, = v0.24.0, < v0.38.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
CVSS v3.1
Score 7.5high
Affected software
AWS
AWS-LC
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-3336) involves improper certificate validation (CWE-295) in the PKCS7_verify() function of AWS-LC. Specifically, when processing PKCS7 objects containing multiple signers, the certificate chain verification can be bypassed for all but the final signer. This flaw could allow an unauthenticated user to circumvent intended certificate validation checks. AWS manages remediation for its cloud services, and users of AWS-LC are advised to upgrade to version 1.69.0 where the issue is fixed.
Potential Impact
The vulnerability allows an unauthenticated attacker to bypass certificate chain verification for multiple signers in PKCS7 objects, potentially undermining the integrity of signature validation processes. This could lead to acceptance of forged or invalid signatures except for the final signer, impacting the trustworthiness of cryptographic operations relying on AWS-LC. There is no indication of confidentiality or availability impact. No known exploits in the wild have been reported.
Mitigation Recommendations
AWS manages remediation for this vulnerability in its cloud services, so customers using AWS services do not need to take action. Applications that directly use AWS-LC should upgrade to AWS-LC version 1.69.0, which contains the official fix for this issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- AMZN
- Date Reserved
- 2026-02-27T15:16:27.359Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Is Cloud Service
- true
- Vendor Advisory Urls
- [{"url":"https://aws.amazon.com/security/security-bulletins/2026-005-AWS/","vendor":"AWS"},{"url":"https://access.redhat.com/security/cve/CVE-2026-3336","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:5459","vendor":"Red Hat"}]
Threat ID: 69a60221d1a09e29cb4eac7d
Added to database: 03/02/2026, 21:33:21 UTC
Last enriched: 07/15/2026, 09:07:51 UTC
Last updated: 09/13/2026, 22:29:46 UTC
Views: 286
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