This second bugfix & security release for 1.8.0 fixes one (potential) bug and closes one (minor) security vulnerability:

🔒 Security fixes

  • Fixed an open redirect vulnerability in the login dialog. An attacker could send a login URL with a specially crafted redirect parameter pointing to an external page under their control to an instance admin that if used to login would redirect this URL, allowing the attacker to start a phishing attack. This is not directly exploitable by the attacker, but after a successful phishing attack and thus obtained credentials could be used to gain access to the OctoPrint instance if somehow reachable by the attacker (e.g. if you have exposed your OctoPrint instance on the public internet or another hostile network contrary to the project’s recommendations). Thanks to “Mizu” for reporting and disclosing this responsibly.

🐛 Bug fixes

  • Pinned the Flask dependency to 2.1. The latest release requires a version of werkzeug that we currently cannot upgrade to due to yet another dependency, and there seem to have been cases in the field where users managed to update Flask regardless of the werkzeug version pin in OctoPrint, which caused runtime errors. This has not been successfully reproduced in the development environment, but a version pin here is a sensible precaution.

You can also take a look at the extremely short changelog on GitHub.

Like every single release (and release candidate) of OctoPrint ever since early 2016 this release was made possible only through your continued support of my work 💕

Issues while updating?

On every new OctoPrint release we see some people run into the same issues with outdated or broken environments all over again. If you encounter a problem during update, please check this collection of the most common issues encountered over the past couple of release cycles first, and test if the included fixes solve your problem.


The heads-ups from 1.8.2 still apply, please read them carefully, they might impact you and how you use OctoPrint! Also see the Further Information and Links below for more information, where to find help and how to roll back.


Thanks to everyone who contributed to this bugfix release and provided full, analyzable bug reports, suggestions and feedback!

Further Information

If connected to the internet, OctoPrint will allow you to apply this update automatically via an update notification. It may take up to 24h for this notification to pop up, so don't be alarmed if it doesn't show up immediately after reading this. You can force the update however via Settings > Software Update > Advanced options > Force check for update.

If your update fails chances are high you are running into one of the common update issues listed with fixes here, so please go through that FAQ entry first.

If you have any problems with your OctoPrint installation, please seek support on the community forum.