High severity · published Jun 23, 2026
CVE-2026-12957
Arbitrary Code Execution in Language Servers for AWS
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
Improper trust boundary enforcement in Language Servers for AWS before version 1.65.0 on all supported platforms may allow a for arbitrary code execution. If a local user opens a maliciously crafted workspace, any commands within the project configuration files may be automatically executed. This issue requires the user to trust the workspace when prompted.
To remediate this issue, users should upgrade to Language Servers for AWS version 1.65.0 or higher.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 14% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LS
Language Servers for AWS · Amazon Web Services
before 1.65.0 · source: vendor
In the news
VulnerabilityHigh
Amazon Q Developer Flaw Could Let Malicious Repos Run Code via MCP Configs
A high-severity flaw in Amazon Q Developer let a malicious repository run commands and steal a developer's cloud credentials. The path was short: a developer opens the repo, trusts the workspace, and Amazon Q does the rest. Amazon has patched it.
Tracked as CVE-2026-12957 (CVSS 8.5), the bug sat in how Amazon's AI coding assistant handled Model Context Protocol (MCP) servers.
Wiz
Jun 26, 2026·The Hacker News
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-12957
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-12957
aws.amazon.com
https://aws.amazon.com/security/security-bulletins/2026-047-aws/
github.com
https://github.com/aws/language-servers/security/advisories/GHSA-xhcr-j4j9-3gh7
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