[Safe Outputs Conformance] SEC-004: artifact_client.cjs flagged for unsanitized body field (HTTP transport payload — needs documented exemption)

[github-actions]

Conformance Check Failure

Check ID: SEC-004
Severity: MEDIUM
Category: Security (Content Sanitization)

Problem Description

The Safe Outputs conformance checker (scripts/check-safe-outputs-conformance.sh) flags actions/setup/js/artifact_client.cjs because it contains a body: field but no sanitization token (sanitize / stripHTML / escapeMarkdown / cleanContent), and carries no @safe-outputs-exempt SEC-004 annotation.

SEC-004 requires that agent-authored content destined for a GitHub API (issue/PR/comment bodies) be sanitized before use. Investigation shows this is a heuristic false positive: the two body occurrences in artifact_client.cjs are HTTP request bodies for the Actions artifact (Twirp) service, not user-authored comment content:

• actions/setup/js/artifact_client.cjs:78 — body: JSON.stringify(body) (Twirp RPC request payload)
• actions/setup/js/artifact_client.cjs:187 — body: fs.createReadStream(filePath) (file upload stream)

Neither value is agent safe-output content written back to a GitHub issue/PR/comment. The correct remediation is to add a documented @safe-outputs-exempt SEC-004 annotation, matching the established pattern already used for transport-payload body references elsewhere in this codebase (mcp_cli_bridge.cjs, mount_mcp_as_cli.cjs, start_mcp_gateway.cjs).

Affected Components

• Files: actions/setup/js/artifact_client.cjs (body at lines 78 and 187)
• Handlers: none — this is the artifact upload/download client, not a safe-output content handler

🔍 Current vs Expected Behavior

Current Behavior

artifact_client.cjs uses body: for HTTP request payloads (a JSON-stringified Twirp request and a file read stream). The SEC-004 heuristic matches body: and, finding no sanitization helper and no exemption annotation, reports a MEDIUM failure.

Expected Behavior

Since these body values are HTTP transport payloads — not agent-authored content reflected into a GitHub API — the file should carry a documented @safe-outputs-exempt SEC-004 annotation explaining the false positive, consistent with the existing transport-payload exemptions in actions/setup/js/.

Remediation Steps

This task can be assigned to a Copilot coding agent:

1. Confirm the two body occurrences in actions/setup/js/artifact_client.cjs (lines 78 and 187) are HTTP request payloads (Twirp JSON request body and an upload file stream), not agent safe-output content.
2. Add a documented exemption annotation near the top of the file in the same style as actions/setup/js/mcp_cli_bridge.cjs, e.g.:
   // @safe-outputs-exempt SEC-004: "body" references are HTTP transport payloads (Twirp RPC request body / artifact upload stream), not user-authored comment bodies.

Verification

After remediation, run:

bash scripts/check-safe-outputs-conformance.sh

The SEC-004 check should report PASS and the Medium Failures count should drop to 0.

References

• Safe Outputs Specification: docs/src/content/docs/specs/safe-outputs-specification.md
• Conformance Checker: scripts/check-safe-outputs-conformance.sh (SEC-004, lines ~135-162)
• Existing exemption pattern: actions/setup/js/mcp_cli_bridge.cjs, actions/setup/js/start_mcp_gateway.cjs
• Run ID: 27400439574

Generated by ✅ Daily Safe Outputs Conformance Checker · 66.5 AIC · ⌖ 12.9 AIC · ⊞ 6.6K · ◷

• expires on Jun 12, 2026, 11:12 PM UTC-08:00

[github-actions]

This issue was automatically closed because it expired on 2026-06-13T07:12:54.588Z.

Closed by Workflow