An issue was discovered in GNU gettext 0.19.8. There is a double free in default_add_message in read-catalog.c, related to an invalid free in po_gram_parse in po-gram-gen.y, as demonstrated by lt-msgfmt.
https://usn.ubuntu.com/3815-2/
https://usn.ubuntu.com/3815-1/
https://github.com/CCCCCrash/POCs/tree/master/Bin/Tools-gettext-0.19.8.1/heapcorruption
https://github.com/CCCCCrash/POCs/tree/master/Bin/Tools-gettext-0.19.8.1/doublefree
https://access.redhat.com/errata/RHSA-2019:3643
http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00065.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00061.html