This advisory has been withdrawn after the maintainers of loguru noted this issue is not a security vulnerability and the CVE has been revoked. We have stopped Dependabot alerts regarding this issue.
Original Description
In versions of loguru up to and including 0.5.3 a lack of sanitization on log serialization can lead to arbitrary code execution. The maintainer disputes the issue, but has altered behavior of the library in commit 4b0070a4f30cbf6d5e12e6274b242b62ea11c81b. See https://github.com/Delgan/loguru/issues/563 for further discussion of the issue. The function in question is intended for internal use only, but is not restricted. This has been patched in version 0.6.0.