||It has been found that setting a master password post-Thunderbird 52 does not delete unencrypted previously stored passwords before Thunderbird 68.5. If a user saved passwords before Thunderbird 60 and then later set a master password, an unencrypted copy of these passwords is still accessible. This is because the older stored password file was not deleted when the data was copied to a new format starting in Thunderbird 60. The new master password is added only on the new file. This could allow the exposure of stored password data outside of user expectations.