cve.bz

CVE-2026-4270

6.8 mediumEPSS 0.1%

Medium (6.8) in amazon aws api mcp server. EPSS 0.1% chance of exploitation in the next 30 days. Fixed in awslabs-aws-api-mcp-server 1.3.9.

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.

Severity

CVSS 4.0

6.8 medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

5.5 medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS
0.1% chance of exploitation in the next 30 days; higher than 2% of CVEs (scores of 2026-10-31)
CWE
CWE-424
Published
Modified
Record from
the NVD, synced

Affected

Packages (OSV)

AdvisoryEcosystemPackageAffectedFixed in
GHSA-2cpp-j2fc-qhp7PyPIawslabs-aws-api-mcp-server>=0.2.14 <1.3.91.3.9
GHSA-2cpp-j2fc-qhp7PyPIawslabs-aws-api-mcp-server>=0.2.14 <1.3.91.3.9
PYSEC-2026-162PyPIawslabs-aws-api-mcp-server>=0.2.14 <1.3.91.3.9

References

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