Ppmd7.c in 7-Zip before 23.00 allows an integer underflow and invalid read operation via a crafted 7Z archive.

7-Zip through 21.07 on Windows allows privilege escalation and command execution when a file with the .7z extension is dragged to the Help>Contents area. This is caused by misconfiguration of 7z.dll and a heap overflow. The command runs in a child process under the 7zFM.exe process. NOTE: multiple third parties have reported that no privilege escalation can occur

Incorrect initialization logic of RAR decoder objects in 7-Zip 18.03 and before can lead to usage of uninitialized memory, allowing remote attackers to cause a denial of service (segmentation fault) or execute arbitrary code via a crafted RAR archive.

7-Zip through 18.01 on Windows implements the "Large memory pages" option by calling the LsaAddAccountRights function to add the SeLockMemoryPrivilege privilege to the user's account, which makes it easier for attackers to bypass intended access restrictions by using this privilege in the context of a sandboxed process.