Dan Goodin, reporting for ArsTechnica:

There’s a critical weakness in the widely used Transmission BitTorrent app that allows websites to execute malicious code on some users’ computers. That’s according to a researcher with Google’s Project Zero vulnerability reporting team, who also warns that other BitTorrent clients are likely similarly susceptible.

The issue is explained here and is said to likely affect other BitTorrent clients too.

Although the flaw was reported to the Transmission developers back in November 2017, an update with a patch has still not been issued. If you’re a Transmission user, you can temporarily disable the “Remote Access” option to mitigate any attacks.