Vulnerability · Published Aug 5, 2026 · Assigned by AMZN

CVE-2026-18953Improper limitation of a pathname to a restricted directory in aws-transform-mcp-server

High 8.6

In plain English

A high-severity path traversal in aws-transform-mcp-server from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.

Severity (CVSS 3.1)8.6High

Exploit odds (30 days)0.2%top 92.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack tooling1Public PoC

Official description

Improper limitation of a pathname to a restricted directory in the get_resource tool in Amazon awslabs.aws-transform-mcp-server 0.1.0 through 0.1.4 might allow a context-dependent actor to write arbitrary files outside the intended working directory via the savePath parameter. To remediate this issue, users should upgrade to version 0.1.5 or later.

Affected products (as reported)

Vendor	Product	Versions
AWS	aws-transform-mcp-server	0.1.0 – through 0.1.4

Weakness: CWE-22 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

References

https://pypi.org/project/awslabs.aws-transform-mcp-server/0.1.5/ release-notes, patch
https://aws.amazon.com/security/security-bulletins/2026-075-aws/ vendor-advisory
https://github.com/awslabs/mcp/security/advisories/GHSA-66mr-jr63-2jgw release-notes