Update (07/02/18): When reached for comment, Samsung sent over the following response:
“We are aware of the reports regarding this matter and our technical teams are looking into. Concerned customers are encouraged to contact us directly at 1-800-SAMSUNG.”
Samsung did not say if there will be an update to fix the issue or when that update will arrive if it does. At least the company acknowledged the bug, though affected device owners should read the original article below and follow the recommended steps.
Original article: If you have the latest version of the Samsung Messages app, you may have had photos from your Gallery app sent to contacts without you knowing about it.
That is what some device owners said on Reddit, where they reported that photos they either sent before or in their entire galleries were distributed without their consent. One owner experienced the issue on their Galaxy Note 8, while others also have the same problem on their Galaxy S9 and S9 Plus units.
The Samsung Messages bug does not seem to be device-specific or network-specific. No one knows where this bug came from, though folks recommended that you disable storage permissions for Samsung Messages. That will prevent the app from pulling photos from the Gallery app.
To disable storage permissions, go to Settings -> Apps -> Samsung Messages -> Permissions -> Storage. Keep in mind that you will not be able to send images or GIFs to other people from within the app if you disable storage permissions.
You can also turn off auto-updates if you go into the Settings menu within Galaxy Apps. You can even throw your hands up in the air and use a different messaging app until Samsung gets its act together.
While you wait, some users suggested that you check the logs on your carrier’s website to see if they caught the issue.