Encode.pm, as distributed in Perl through 5.34.0, allows local users to gain privileges via a Trojan horse Encode::ConfigLocal library (in the current working directory) that preempts dynamic module loading. Exploitation requires an unusual configuration, and certain 2021 versions of Encode.pm (3.05 through 3.11). This issue occurs because the || operator evaluates @INC in a scalar context, and thus @INC has only an integer value.
https://security.netapp.com/advisory/ntap-20210909-0003/
https://security-tracker.debian.org/tracker/CVE-2021-36770
https://news.cpanel.com/unscheduled-tsr-10-august-2021/
https://metacpan.org/dist/Encode/changes
https://github.com/dankogai/p5-encode/commit/527e482dc70b035d0df4f8c77a00d81f8d775c74
https://github.com/Perl/perl5/commit/c1a937fef07c061600a0078f4cb53fe9c2136bb9