CVE-2026-4270GHSA-2CPP-J2FC-QHP7PYSEC-2026-162
AWS API MCP File Access Restriction Bypass
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 1.3.9
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
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.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- AWS AWS API MCP Server
From 0.2.14 · fixed in 1.3.9
- awslabs-aws-api-mcp-serverPyPI
From 0.2.14 · fixed in 1.3.9