v0.7.3

2026.10.12 Release v0.7.3

32 commits from 15 contributors.

⭐ Highlights

• Fixed intermittent network failures when accessing sandboxes, improving network stability.
• Improved the S3lvol cache, making cross-node restore faster.
• S3lvol hot upgrade: faster I/O recovery during component upgrades.

🎯 Major Features

MCP support (E2B compatible)

Sandboxes can now be created with an E2B-compatible mcp parameter, which starts an MCP (Model Context Protocol) gateway inside the sandbox:

• The Python / Node / Go SDKs all support it and return the MCP URL and token.
• The gateway can be replaced with any custom implementation that follows the contract. Cube provides a reference implementation under examples/mcp-gateway.

✨ Enhancements

Templates & Storage

• S3lvol hot upgrade: the sandbox I/O pause during an upgrade drops sharply, from about 40 s to about 8 s (#1822).
• Cross-node restore no longer copies the whole disk to the node. A restored sandbox lazy-loads on demand, and repeated data can be accelerated by the local cache (#1898).
• Template creation now checks node validity up front and fails immediately when a problem is found, improving the create experience (#1829).

Lifecycle & Control Plane

• Pause is faster: the pause implementation was optimized. A single pause is ~41% faster (150 ms → 88 ms for a 2 GiB sandbox), and ~20% faster under concurrency 50 (#1731).

Deployment & Runtime

• PVM host / guest kernel updated from 6.6.69 to 6.6.117 (#1852).

Web UI / CubeOps / Other

• Template cards in the Web UI now show the template alias (#1876).

🐛 Bug Fixes

Lifecycle & Sandbox

• Fixed paused sandboxes losing metadata (labels, template, specs, volume mounts) in Info queries, introduced in v0.7.0 (#1861).
• Fixed occasional clones failing with no more resource (#1909).
• Fixed the template list hanging once the cluster had many templates (#1899); the list API and cubemastercli tpl ls now support paging (limit / offset).
• Fixed occasional resource-reclaim issues when deleting a sandbox (#1810).
• Fixed rare block I/O truncation or hangs (#1825).
• Fixed create-from-snapshot rejecting re-sent volumeMounts with "must have exactly one declaration" (#1894).

Networking & Security

• Fixed 5-tuple conflicts when accessing a sandbox, which caused intermittent network failures (#1915).
• Improved session reclamation so cleanup is more efficient (#1914).
• Fixed connections being reset when a sandbox NIC was reused (#1919).
• Fixed session state not being refreshed (#1918).

Deployment & Upgrade

• Reduced noisy cgroup v2 error logs (#1869).
• Fixed cubemastercli accumulating zombie processes; a one-time pod restart clears existing ones (#1860).

Other

• Fixed creating a sandbox from a deleted snapshot returning HTTP 500, which SDKs kept retrying (#1868).
• Fixed the Go SDK Watcher closing twice under concurrency (#1405).