CVE-2026-12957
HIGH · 7.8 EPSS 0.1%Vendor patched, researcher confirmed, real attack chain disclosed; no in-the-wild confirmation yet.
What: Improper trust boundary enforcement in Language Servers for AWS (Amazon Q Developer extension) before v1.65.0 allows arbitrary code execution and cloud credential theft when a developer opens a malicious workspace. CVSS 7.8 (HIGH).
Why it matters: AWS has issued a patch (v1.65.0+); researcher (Wiz) disclosed the flaw with real-world attack chain (malicious repo → MCP config execution → credential exfiltration). Social chatter reflects urgent patching guidance and defender triage activity. Not yet KEV-listed but vendor-acknowledged with remediation.
Where it's seen: Security researcher disclosure, vendor advisory, multi-language social amplification, defender guidance posts emphasizing immediate upgrade and repo-trust hygiene.
RISK: HIGH — Affects developer environments; cloud credential exposure; patch available but adoption tracking unclear.
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 3.1 breakdown
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 required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High