In today’s cybersecurity landscape, vulnerabilities are an ongoing reality for all software vendors, and open source projects are no exception. We take our responsibility to identify, address and communicate security issues very seriously, including towards our community.

We were recently made aware that a vulnerability affecting Xen Orchestra (VSA-2026-062) was being actively exploited by a threat actor. Our teams mobilized immediately. The vulnerability was under embargo; the embargo has now been lifted, and we fast-tracked a patch in line with our vulnerability handling process. The vulnerability is now fixed.

Most Xen Orchestra deployments are not exposed to the public Internet, which greatly reduces the likelihood of exploitation. If your Xen Orchestra is reachable from the public Internet, however, urgent action is strongly advised.

If you run Xen Orchestra from sources

1. Update to the latest master, which includes the fix from pull request #10748, then rebuild and restart xo-server as usual.
2. Restrict access right away if Xen Orchestra is reachable from the Internet: VPN, dedicated management network or IP allow-list.
3. Revoke all active sessions and API tokens, then rotate the secrets used in your stack: the root password of every XCP-ng host, XO proxy credentials, backup remotes (NFS, S3, etc.), XO user passwords and OTP secrets.
4. Check for compromise: watch for unexpected VMs, imports or sessions, check the indicators of compromise listed in the advisory, and implement the blocking countermeasures it describes.

If you use a Xen Orchestra Appliance (XOA): update to 6.10.1 (latest channel) or 6.9.2 (stable channel). In XO 5, go to XOA > Updates and click Upgrade.

All instructions are centralized in the advisory, which will be updated as new information becomes available:
https://docs.vates.tech/security-advisories/advisories/2026/vates-sa-2026-062/

A reminder that applies to any product: a virtualization management plane should never be exposed to the whole Internet, however up to date it is. A VPN and a dedicated management network remain the best protection against the next unknown vulnerability.

If you have questions, feel free to ask in this thread. Please don’t post logs or details that could expose your infrastructure publicly.