Vulnerability in Amazon AWS-LC (CVE-2026-4428)
Summary
Vulnerability in Amazon AWS-LC (CVE-2026-4428). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
Bulletin ID: 2026-010-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 2026/03/19 13:30 PM PDT Description: AWS-LC is a general-purpose cryptographic library maintained by AWS. We identified CVE-2026-4428 affecting X.509 certificate verification. A logic error in the CRL (Certificate Revocation List) distribution point matching in AWS-LC allows a revoked certificate to bypass revocation checks during certificate validation, when the application enables CRL checking and uses partitioned CRLs with Issuing Distribution Point (IDP) extensions. Applications that do not enable CRL checking (X509_V_FLAG_CRL_CHECK) are not affected. Applications using complete (non-partitioned) CRLs without IDP extensions are also not affected. Impacted versions: - CRL Distribution Point Scope Check Logic Error in AWS-LC >= v1.24.0, < v1.71.0 - CRL Distribution Point Scope Check Logic Error in AWS-LC-FIPS >= AWS-LC-FIPS-3.0.0, < AWS-LC-FIPS-3.3.0 - CRL Distribution Point Scope Check Logic Error in aws-lc-sys >= v0.15.0, < v0.39.0 - CRL Distribution Point Scope Check Logic Error in aws-lc-fips-sys >= v0.13.0, < v0.13.13 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
Source: AWS Security Bulletins NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-4428 has been found in Amazon AWS-LC.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Amazon AWS-LC CVE-2026-4428" on the vendor's site.
CVE-2026-4428 (Amazon AWS-LC)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Amazon AWS-LC.
Check the vendor advisory for the affected versions of Amazon AWS-LC.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'AWS-LC' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'AWS-LC' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
AWS-LCを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- AWS aws.amazon.com