In previous versions of systemd, the default coredump behavior included writing a POSIX ACL to the core file allowing the user that was running the dumped process to view the coredump. This behavior stopped after 239-82.0.3.el8_10.5 (systemd-239-82.0.4.el8_10.5 appears to be the first of the broken versions, and all subsequent versions up to the current 239-82.0.5.el8_10.5 are similarly broken).

The changelog for 239-82.0.4.el8_10.5 indicates that a "%d" was added to the coredump pattern, but removing this "%d" from the pattern was not sufficient to restore the ACL functionality:

# sysctl -w kernel.core_pattern='|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e'
kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e

This was generated with systemd-239.82.0.5.el8_10.5:

# file: core.sleep.1000.9a350d932b254a8d880f502cd4a2ae66.11340.1758137548000000.lz4
# owner: root
# group: root
user::rw-
group::r--
other::---

This was generated with systemd-239.82.0.3.el8_10.5:

# file: core.sleep.1000.9a350d932b254a8d880f502cd4a2ae66.5924.1758137198000000.lz4
# owner: root
# group: root
user::rw-
user:sx:r--
group::r--
mask::r--
other::---