This medium-severity CVE scores 5.5 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 94% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
Improper Protection of Alternate Path exists in the no-access and workdir feature of the AWS API MCP Server versions >= 0.2.14 and < 1.3.9 on all platforms may allow the bypass of intended file access restriction and expose arbitrary local file contents in the MCP client application context.
To remediate this issue, users should upgrade to version 1.3.9.
March 16, 2026
May 21, 2026
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| awslabs-aws-api-mcp-server | 0.2.14 ... 1.3.8 (31 versions) | 1.3.9 | — |
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
CWE-424
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-4270
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.