For example, deleting files from a user's computer, or transferring personal data from a user's computer to someone?
Nearly all open source licenses include a disclaimer of warranty and a limitation of liability, including the GPLv3 (see sections 15–17). However, whether and to which extent such disclaimers are possible depends on the user's local jurisdiction. Maybe you are liable, maybe you are not.
In practice, as long as you show a good faith effort to write working code, you will be fine. That means: don't knowingly write malicious code. If in doubt, at least review the status of the law in your home jurisdiction, and possibly in larger jurisdictions where your software might be used.
Note that a disclaimer of warranties does not free you from other legal obligations you might have. For example, if an application collects usage analytics, that would likely have to comply with the EU-GDPR. And cryptographic software might be subject to export controls. Open source cannot be a carte blanche to write software that would otherwise be illegal.