Build1 distinct publisher3 min readUpdated
Wiz says the VS Code extension auto-loaded MCP server configs from the workspace and handed spawned processes the developer's full environment. Fixed in language server 1.65.0.
The Engineer · Build desk

Compiled by The EngineerSomething wrong?How this is made
Wiz Research has disclosed a high-severity vulnerability in the Amazon Q Developer extension for Visual Studio Code that allowed arbitrary code execution and cloud credential theft simply because a developer opened a malicious repository [1]. Amazon has remediated it in language server version 1.65.0 [2], but Wiz frames the finding as part of a broader pattern across AI coding tools, with OX Security and Check Point publishing similar findings around the same time [3].
The mechanism is unglamorous, which is the point. According to Wiz, the extension loaded `.amazonq/mcp.json` from the workspace root immediately on opening the folder, with no approval dialog and no workspace trust check [4]. The second half of the problem is that the processes it spawned inherited the user's complete environment [5]. The Model Context Protocol exists precisely so assistants can spawn local processes and reach external services [6], and its security model assumes the user configured those servers on purpose [7]. A file that arrives with a `git clone` is not that.
Wiz's proof of concept is four steps: the victim clones a repository, perhaps a typosquatted package or a malicious pull request, opens the folder in VS Code with Amazon Q installed, activates Amazon Q, and the extension loads and executes the attacker's MCP configuration without prompting [8]. In testing, `aws sts get-caller-identity` captured the developer's active AWS session, escalating local execution into cloud compromise [9]. The only human actions required were opening the folder and activating the assistant [10].
The underlying issue is a trust boundary that developers have been trained to ignore. Wiz notes that opening a project folder already means implicitly trusting dozens of configuration files, including `package.json`, `.vscode/settings.json` and `.eslintrc`, most of which are declarative and do not execute code themselves [11]. Extensions blur that line when they read workspace-specific configs and act on them automatically [12]. Malicious config then runs before the developer has reviewed a single line of code [13].
Treat this as an audit task rather than a patch. Confirm the Amazon Q language server version deployed on developer machines is at or above the remediated 1.65.0 [2]; extension version numbers are not the same thing as the language server version that carries the fix. Then enumerate, for every AI assistant your engineers have installed, which per-repository paths it reads and whether any of them can start a process. The dangerous property is not MCP itself but the combination Wiz identified: repo-supplied configuration plus automatic startup plus inherited environment [1][5]. Any one of those alone is survivable.
Two things worth watching. First, whether vendors move MCP server startup behind VS Code's workspace trust model, since Wiz specifically records the absence of a trust check as one of the two root causes [4]. Second, whether assistants stop passing the full parent environment to spawned servers, because as long as they do, every credential in a developer's shell is in scope for anything the repo can start [5]. Given that three separate research teams landed on the same class of defect at roughly the same time [3], the remaining question is how many shipped assistants have not yet been looked at.
Follow any of these and your For You feed starts watching them — no settings page required.
Ranked by verification strength, evidence, and original report placement.
Wiz Research discovered a high-severity vulnerability in the Amazon Q Developer Extension for Visual Studio Code that allowed attackers to achieve arbitrary code execution and cloud credential theft simply by having a developer open a malicious repository; Amazon Q automatically loaded MCP server configurations from workspace files without user consent, and combined with full environment inheritance this enabled immediate code execution.
A single malicious config file could execute arbitrary commands with full access to the developer's credentials, with no user interaction required beyond opening the folder and activating Amazon Q.
Opening a project folder in VS Code means implicitly trusting dozens of configuration files, including package.json, .vscode/settings.json and .eslintrc, most of which are declarative and configure behavior without executing code directly.
Extensions often blur the declarative boundary by reading workspace-specific configs and acting on them automatically.
The result is that a developer clones a seemingly legitimate repository, opens it in their IDE, and malicious configs execute before they have reviewed a single line of code.
Amazon has remediated the issue in language server version 1.65.0.
Evidence-backed comparisons of source perspectives and observed adoption signals. Read the methodology
Which Builder, Operator, and Investor concerns the observed source mix emphasized—not a truth score.
Evidence, demonstrated adoption, hype gap, incentives, and confidence are assessed independently, each on its own current evidence. How these are measured.
Detailed first-party research, single publisher
The mechanism is described at file-path and process-behavior granularity, with a reproducible attack chain and a named fix version, which is strong for a vulnerability writeup. It is nonetheless one source authored by the discoverer, with no CVE identifier, no vendor advisory, no disclosure timeline and no independent replication in the cluster, which caps the score.
Patch shipped, exposure unmeasured
There is one hard adoption-side fact: Amazon shipped a remediation in language server 1.65.0, alongside a public disclosure event. Nothing in the cluster quantifies how many Amazon Q installs were vulnerable, how many have upgraded, or whether the technique was used in the wild, so real-world reach cannot be scored higher.
Specific bug solid, systemic framing ahead of shown evidence
The Amazon Q findings are well documented and already patched, so the core is not overstated. The framing that MCP auto-execution is a systemic, industry-wide risk runs modestly ahead of what this cluster shows, since the corroborating third-party findings are named but not detailed and no exploitation-in-the-wild or exposure data is offered.
Vendor-authored research with brand incentive
The sole source is the research blog of a cloud security vendor whose commercial interest aligns with elevating cloud-credential and AI-tooling risk, and which frames the finding as requiring industry-wide attention. That does not undercut the technical detail, but there is no non-vendor voice, no Amazon response and no adversarial review in the cluster to balance it.
High confidence in the bug, low in the generalization
Confidence is solid on the specific extension behavior, the proof of concept and the remediated version because they are described precisely by the party that found them. It is held down by single-publisher sourcing, vendor authorship, absent CVE and advisory anchors, and no measurement of affected or patched populations.
build
The only way to prove a contract test can fail is to ship a server that lies1 distinct publisher
build
MCP 2026-07-28 drops the `result` wrapper, and your unit tests will not notice1 distinct publisher
product
Twin1's $20M bet: the unit of enterprise AI is one employee, not the org1 distinct publisher
science
OX Security says MCP command execution is a design choice, so server owners own the risk1 distinct publisher
Distinct publishers with included, body-backed reporting in this cluster.
1 article · August 19, 2026