CVE-2026-4270: AWS API MCP File Access Restriction Bypass
AWS · AWS API MCP Server
Vendor fix available · Affected: AWS API MCP Server · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 4% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- AWS · AWS API MCP Serverfrom 0.2.14 before 1.3.9
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- AWS
- Published
- March 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-4270 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.