In Zsh before 5.8, attackers able to execute commands can regain privileges dropped by the --no-PRIVILEGED option. Zsh fails to overwrite the saved uid, so the original privileges can be restored by executing MODULE_PATH=/dir/with/module zmodload with a module that calls setuid().
seclists.org/fulldisclosure/2020/May/49
seclists.org/fulldisclosure/2020/May/53
seclists.org/fulldisclosure/2020/May/55
seclists.org/fulldisclosure/2020/May/59
zsh.sourceforge.net/releases.html
github.com/XMB5/zsh-privileged-upgrade
lists.debian.org/debian-lts-announce/2020/03/msg00004.html
lists.debian.org/debian-lts-announce/2020/12/msg00000.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FP64FFIZI2CKQOEAOI5A72PVQULE7ZZC/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PN5V7MPHRRP7QNHOEK56S7QGRU53WUN6/
security.gentoo.org/glsa/202003-55
support.apple.com/HT211168
support.apple.com/HT211170
support.apple.com/HT211171
support.apple.com/HT211175
support.apple.com/kb/HT211168
support.apple.com/kb/HT211170
support.apple.com/kb/HT211171
support.apple.com/kb/HT211175
www.zsh.org/mla/zsh-announce/141