This is a command-line tool to manipulate passwords stored in GNOME Keyring as well as any other service implementing Secret Service D-Bus API. This particular program is focused on full API coverage and convenient batch-processing.

Here's an example:

clibsecret foo bar --info '%i %A %v ' | sed 's/\bbar\b/baz/' | clibsecret --read '%i %A %v '

This command searches for all passwords with tag foo=bar and changes it to baz. (\b stands for word boundary, if you're curious.)
For more info, see supplied man page.