Security fixes are applied to the latest Windows release and the latest server container image. Older releases should be upgraded before reporting a problem.

For source installations, use a clean virtual environment and install the current requirements. Candidate minimum versions are Flask 3.1.3, Requests 2.33.0 and Pillow 12.3.0. The previous ranges permitted older releases with known advisories, even when a fresh installation normally selected a newer version. Updating these files does not upgrade an existing virtual environment, container or frozen EXE.

These floors address the reviewed upstream advisories, not every hypothetical application exploit. For example, the Requests temporary-file advisory applies to direct callers of extract_zipped_paths(), which Clipboard Bridge does not call; the Flask cache advisory also has deployment-specific preconditions. Pillow handles untrusted image data, so its image-parser fixes remain important on a trusted LAN.

When reviewing updates, audit both the freshly resolved dependency set (including transitive dependencies) and the declared direct minimum versions. Deduplicate advisory IDs before counting findings. Recheck at release time; a clean audit is time-specific and is not a security certification of already-published binaries. Major upgrades such as Gunicorn's pending update require their own compatibility review and running-container tests, not just a manifest change.

Upstream references: Flask session/cache advisory, Requests temporary-file advisory, Pillow 12.3.0 security release notes.

Do not open a public issue for a vulnerability or include credentials, clipboard contents, private addresses or logs containing sensitive data.

Use the repository's private vulnerability reporting form. Include the affected version, operating system, deployment method, reproduction steps and expected impact. Remove real tokens and passwords from screenshots and logs.

Clipboard Bridge is designed for trusted local networks and private VPNs. The default HTTP transport is intentionally compatible with iOS Shortcuts and does not encrypt traffic by itself. Do not expose port 5088 directly to the public Internet. For remote access, use a private VPN or an HTTPS reverse proxy and enable the available token, web password or isolated accounts.

Tokens, the web password and isolated accounts are optional. Without them, the general clipboard is open to the local network. Shortcut and account URLs can contain token, user and password in plain text; these values can appear in browser history, logs and screenshots. Treat every such URL as a credential.

The project does not collect telemetry or receive users' clipboard contents.

From Windows 2.0.18, the optional update feature contacts the official GitHub Releases API (automatic checks default on) and downloads from GitHub when requested or when automatic installation is explicitly enabled. GitHub sees normal network request metadata, such as the client's IP address. Clipboard contents and clipboard server/account credentials are never sent with these requests. Disable automatic checks in Settings > Updates to stop background GitHub requests.

Updates require exact official assets, SHA-256, size and PE version/architecture checks. This does not authenticate an independent publisher if the GitHub project itself is compromised. Windows packages remain unsigned; Internet-zone checks and Windows approval decisions are preserved, not bypassed. Automatic installation is off by default and may not be unattended on a security policy that blocks unsigned files. The helper changes only app executables and its own private update cache; it does not erase the user profile or force-close applications. An explicit UI commit is required before the helper may replace files, and cancellation withdraws that commit. Release discovery is bounded to 200 entries and fails explicitly if truncated. Cache cleanup removes only recognized expired attempt files; unfinished helper tickets and unrelated files are preserved.

Native clients and Apple Shortcuts retain compatible account URLs. Optional HTTP headers are also supported by the standalone API, but neither form encrypts credentials over HTTP. No interactive login, pairing or token renewal is required. Windows currently uses HTTP; Android and Apple can use an optional HTTPS endpoint. Keep Windows connections on a trusted LAN/VPN rather than promising universal TLS.

The Windows embedded server exposes one shared clipboard and does not implement the standalone server's account/token login. Use it only on a trusted LAN or a private VPN whose access rules admit trusted devices. Do not forward its port.

Windows configuration and Android app-private preferences currently store credentials without application-level encryption. Local clipboard histories are also sensitive. Protect your OS account and backups. DPAPI would protect against some offline reads, not malware running as the same signed-in user; an encrypted configuration migration is deferred until downgrade/recovery behavior is tested.

Remembered web sessions default to 3650 days for compatibility. Administrators can set CLIPBOARD_SESSION_DAYS (1..3650); 90 or 365 is a less persistent choice. Changing a password does not currently revoke all existing browser sessions. For immediate revocation, stop the service, replace /data/secret.key, then restart it: all devices must log in again, but clipboard files are untouched. Back up securely first. Keep this disruptive action separate from routine upgrades.

On case-insensitive or filename-normalizing storage, different account names can refer to the same directory. The candidate account-storage guard refuses access to such ambiguous accounts rather than exposing shared history. Prefer names that do not differ only by case or trailing dots. Back up and review any existing mixed history before changing account names; the application does not automatically move or reassign that data. See account storage recovery.