github/github-mcp-server · error

failed to read response body: %w

Error message

failed to read response body: %w

What it means

list_global_security_advisories received a non-200 response and reading that error body failed. The real status - typically 422 bad filter, 403 rate limit, or 5xx - is masked by this secondary transport failure, so the visible message describes only the failed body read.

Source

Thrown at pkg/github/security_advisories.go:197

				opts.Published = &published
			}
			if updated != "" {
				opts.Updated = &updated
			}
			if modified != "" {
				opts.Modified = &modified
			}

			advisories, resp, err := client.SecurityAdvisories.ListGlobalSecurityAdvisories(ctx, opts)
			if err != nil {
				return nil, nil, fmt.Errorf("failed to list global security advisories: %w", err)
			}
			defer func() { _ = resp.Body.Close() }()

			if resp.StatusCode != http.StatusOK {
				body, err := io.ReadAll(resp.Body)
				if err != nil {
					return nil, nil, fmt.Errorf("failed to read response body: %w", err)
				}
				return ghErrors.NewGitHubAPIStatusErrorResponse(ctx, "failed to list advisories", resp, body), nil, nil
			}

			r, err := json.Marshal(advisories)
			if err != nil {
				return nil, nil, fmt.Errorf("failed to marshal advisories: %w", err)
			}

			result := utils.NewToolResultText(string(r))
			// Global advisories come from the world-readable GitHub Advisory
			// Database (public) but contain externally authored prose
			// (untrusted).
			result = attachStaticIFCLabel(ctx, deps, result, ifc.LabelGlobalSecurityAdvisory())
			return result, nil, nil
		},
	)
}

View on GitHub (pinned to 0ea1f775a7)

Solutions

1. Retry once - usually transient
2. If it repeats, review the filter arguments (ecosystem, affects, date ranges) that likely caused the underlying 4xx
3. Patch the handler to include resp.StatusCode when the body is unreadable

Example fix

// after
return nil, nil, fmt.Errorf("failed to list advisories: status %d (body unreadable: %w)", resp.StatusCode, err)

func isBodyReadFailure(err error) bool {
	var netErr net.Error
	return errors.As(err, &netErr) || errors.Is(err, io.ErrUnexpectedEOF)
}

result, extra, err := callTool(ctx, "list_global_security_advisories", args)
if err != nil && strings.Contains(err.Error(), "failed to read response body") {
    result, extra, err = callTool(ctx, "list_global_security_advisories", args)
}
if err != nil {
    return fmt.Errorf("advisory listing failed (status masked): %w", err)
}

When it happens

Trigger: Non-2xx from ListGlobalSecurityAdvisories followed by a connection break or context cancellation while the error body streamed; deadlines expiring just after headers arrive.

Common situations: Marginal networks; hard timeouts in front of the MCP server; rare in stable environments.

Related errors

• failed to read response body: %w
• failed to read response body: %w
• failed to read response body: %w
• failed to read file content: %w
• GitHub App authentication requires a private key: set GITHUB

AI-assisted analysis of github/github-mcp-server@0ea1f775a7 (2026-08-15). Data as JSON: /api/errors/6b6c25e7de5a082b. Report an issue: GitHub.